diff --git a/code/__DEFINES/flags.dm b/code/__DEFINES/flags.dm
index 5c941e3689ab..c9b4aa597b57 100644
--- a/code/__DEFINES/flags.dm
+++ b/code/__DEFINES/flags.dm
@@ -113,6 +113,9 @@ GLOBAL_LIST_INIT(bitflags, list(1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 204
 #define NO_CLEARING (1<<7)
 
 #define TURF_WEATHER (1<<8) //monkestation edit
+/// This atom is a pseudo-floor that blocks map generation's checkPlaceAtom() from placing things like trees ontop of it.
+#define TURF_BLOCKS_POPULATE_TERRAIN_FLORAFEATURES (1<<9)
+
 ////////////////Area flags\\\\\\\\\\\\\\
 /// If it's a valid territory for cult summoning or the CRAB-17 phone to spawn
 #define VALID_TERRITORY (1<<0)
diff --git a/code/__DEFINES/icon_smoothing.dm b/code/__DEFINES/icon_smoothing.dm
index c96f2b1ac4f6..3a6fb062bb73 100644
--- a/code/__DEFINES/icon_smoothing.dm
+++ b/code/__DEFINES/icon_smoothing.dm
@@ -114,7 +114,9 @@ DEFINE_BITFIELD(smoothing_flags, list(
 #define SMOOTH_GROUP_LOWERED_PLASTEEL S_TURF(61)
 #define SMOOTH_GROUP_FISSURE S_TURF(62)
 
-#define MAX_S_TURF 62 //Always match this value with the one above it.
+#define SMOOTH_GROUP_MUSHROOM S_TURF(63)
+
+#define MAX_S_TURF 63 //Always match this value with the one above it.
 
 #define S_OBJ(num) ("-" + #num + ",")
 /* /obj included */
diff --git a/code/__DEFINES/~monkestation/atmospherics.dm b/code/__DEFINES/~monkestation/atmospherics.dm
new file mode 100644
index 000000000000..78184de5902d
--- /dev/null
+++ b/code/__DEFINES/~monkestation/atmospherics.dm
@@ -0,0 +1,2 @@
+//ATMOS MIX IDS
+#define FOREST_DEFAULT_ATMOS "FOREST_ATMOS"
diff --git a/code/__DEFINES/~monkestation/blackboard.dm b/code/__DEFINES/~monkestation/blackboard.dm
new file mode 100644
index 000000000000..16ac4d6ec3c9
--- /dev/null
+++ b/code/__DEFINES/~monkestation/blackboard.dm
@@ -0,0 +1,27 @@
+
+// Hiding AI blackboard keys
+
+/// Whether or not the mob is currently hiding.
+#define BB_HIDING_HIDDEN "BB_hiding_hidden"
+/// The typecache (populated on `Initialize()` with the first argument of
+/// `/datum/element/can_hide/basic/New()`) of turfs that our mob can hide onto.
+#define BB_HIDING_CAN_HIDE_ON "BB_hiding_can_hide_on"
+/// The aggro range the mob has when hiding.
+#define BB_HIDING_AGGRO_RANGE "BB_hiding_aggro_range"
+/// The aggro range the mob has when NOT hiding (set dynamically).
+#define BB_HIDING_AGGRO_RANGE_NOT_HIDING "BB_hiding_aggro_range_not_hiding"
+/// The cooldown before the mob can hide again (set dynamically).
+#define BB_HIDING_COOLDOWN_BEFORE_HIDING "BB_hiding_cooldown_before_hiding"
+/// The cooldown before the mob can stop hiding (set dynamically).
+#define BB_HIDING_COOLDOWN_BEFORE_STOP_HIDING "BB_hiding_cooldown_before_stop_hiding"
+/// The minimum value for the cooldown before the mob can hide / come out of hiding again.
+#define BB_HIDING_COOLDOWN_MINIMUM "BB_hiding_cooldown_minimum"
+/// The maximum value for the cooldown before the mob can hide / come out of hiding again.
+#define BB_HIDING_COOLDOWN_MAXIMUM "BB_hiding_cooldown_maximum"
+/// The probability (in %) that the mob will stop hiding randomly every process.
+#define BB_HIDING_RANDOM_STOP_HIDING_CHANCE "BB_hiding_random_stop_hiding_chance"
+
+/// The default vision range when hiding, if none is specified.
+#define DEFAULT_HIDING_AGGRO_RANGE 2
+/// The default chance to get out of hiding for every random hiding subtree process.
+#define DEFAULT_RANDOM_STOP_HIDING_CHANCE 2
diff --git a/code/__DEFINES/~monkestation/colors.dm b/code/__DEFINES/~monkestation/colors.dm
index e47cb8ddfddd..60cd738f7873 100644
--- a/code/__DEFINES/~monkestation/colors.dm
+++ b/code/__DEFINES/~monkestation/colors.dm
@@ -1 +1,13 @@
 #define LIGHT_COLOR_CLOCKWORK "#BE8700"
+
+//Colors for Bioluminescence plant traits.
+#define COLOR_BIOLUMINESCENCE_STANDARD "#C3E381"
+#define COLOR_BIOLUMINESCENCE_SHADOW "#AAD84B"
+#define COLOR_BIOLUMINESCENCE_YELLOW "#FFFF66"
+#define COLOR_BIOLUMINESCENCE_GREEN "#99FF99"
+#define COLOR_BIOLUMINESCENCE_BLUE "#6699FF"
+#define COLOR_BIOLUMINESCENCE_PURPLE "#D966FF"
+#define COLOR_BIOLUMINESCENCE_PINK "#FFB3DA"
+
+#define LIGHT_RANGE_FIRE_BLOSSOM_HARVESTED 2.7
+#define LIGHT_POWER_FIRE_BLOSSOM_HARVESTED 1.5
diff --git a/code/__DEFINES/~monkestation/dcs/signals/signals_atom.dm b/code/__DEFINES/~monkestation/dcs/signals/signals_atom.dm
index 4e3566280e4f..a0a10db279d7 100644
--- a/code/__DEFINES/~monkestation/dcs/signals/signals_atom.dm
+++ b/code/__DEFINES/~monkestation/dcs/signals/signals_atom.dm
@@ -17,3 +17,10 @@
 /// Mob is trying to open the hacking menu of a target [/atom], from /datum/hacking/interactable(): (mob/user)
 #define COMSIG_TRY_HACKING_INTERACT "try_hacking_interact"
 	#define COMPONENT_CANT_INTERACT_HACKING (1<<0)
+
+
+/// The signal sent when an atom/movable should try to toggle their hiding.
+/// Gets called on the target, with (hiding, play_feedback = TRUE) as its args.
+/// Used for `/datum/element/can_hide`
+#define COMSIG_MOVABLE_TOGGLE_HIDING "movable_toggle_hiding"
+
diff --git a/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm b/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm
index 245bac0eab7b..8ad59ba2bf15 100644
--- a/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm
+++ b/code/datums/ai/basic_mobs/basic_ai_behaviors/targeting.dm
@@ -76,7 +76,7 @@ GLOBAL_LIST_INIT(target_interested_atoms, typecacheof(list(/mob, /obj/machinery/
 /datum/ai_behavior/find_potential_targets/proc/failed_to_find_anyone(datum/ai_controller/controller, target_key, targeting_strategy_key, hiding_location_key)
 	var/aggro_range = controller.blackboard[aggro_range_key] || vision_range
 	// takes the larger between our range() input and our implicit hearers() input (world.view)
-	aggro_range = max(aggro_range, ROUND_UP(max(getviewsize(world.view)) / 2))
+	// aggro_range = max(aggro_range, ROUND_UP(max(getviewsize(world.view)) / 2)) MAPEXPANSION CHANGE: Stillcaps
 	// Alright, here's the interesting bit
 	// We're gonna use this max range to hook into a proximity field so we can just await someone interesting to come along
 	// Rather then trying to check every few seconds
diff --git a/code/datums/mapgen/CaveGenerator.dm b/code/datums/mapgen/CaveGenerator.dm
index c7420dd8ffa6..ad27001ff7a9 100644
--- a/code/datums/mapgen/CaveGenerator.dm
+++ b/code/datums/mapgen/CaveGenerator.dm
@@ -54,7 +54,7 @@
 	///Base chance of spawning flora
 	var/flora_spawn_chance = 2
 	///Base chance of spawning features
-	var/feature_spawn_chance = 0.15
+	var/feature_spawn_chance = 0.25
 	///Unique ID for this spawner
 	var/string_gen
 
@@ -83,10 +83,19 @@
 		weighted_megafauna_spawn_list = GLOB.megafauna_spawn_list
 	megafauna_spawn_list = expand_weights(weighted_megafauna_spawn_list)
 	if(!weighted_flora_spawn_list)
-		weighted_flora_spawn_list = list(/obj/structure/flora/ash/leaf_shroom = 2 , /obj/structure/flora/ash/cap_shroom = 2 , /obj/structure/flora/ash/stem_shroom = 2 , /obj/structure/flora/ash/cacti = 1, /obj/structure/flora/ash/tall_shroom = 2, /obj/structure/flora/ash/seraka = 2)
+		weighted_flora_spawn_list = list(
+			/obj/structure/flora/ash/leaf_shroom = 2,
+			/obj/structure/flora/ash/cap_shroom = 2,
+			/obj/structure/flora/ash/stem_shroom = 2,
+			/obj/structure/flora/ash/cacti = 1,
+			/obj/structure/flora/ash/tall_shroom = 2,
+			/obj/structure/flora/ash/seraka = 2,
+		)
 	flora_spawn_list = expand_weights(weighted_flora_spawn_list)
 	if(!weighted_feature_spawn_list)
-		weighted_feature_spawn_list = list(/obj/structure/geyser/random = 1)
+		weighted_feature_spawn_list = list(
+			/obj/structure/geyser/random = 1,
+		)
 	feature_spawn_list = expand_weights(weighted_feature_spawn_list)
 	open_turf_types = expand_weights(weighted_open_turf_types)
 	closed_turf_types = expand_weights(weighted_closed_turf_types)
@@ -103,14 +112,7 @@
 	var/start_time = REALTIMEOFDAY
 	string_gen = rustg_cnoise_generate("[initial_closed_chance]", "[smoothing_iterations]", "[birth_limit]", "[death_limit]", "[world.maxx]", "[world.maxy]") //Generate the raw CA data
 
-	// Area var pullouts to make accessing in the loop faster
-	var/flora_allowed = (generate_in.area_flags & FLORA_ALLOWED) && length(flora_spawn_list)
-	var/feature_allowed = (generate_in.area_flags & FLORA_ALLOWED) && length(feature_spawn_list)
-	var/mobs_allowed = (generate_in.area_flags & MOB_SPAWN_ALLOWED) && length(mob_spawn_list)
-	var/megas_allowed = (generate_in.area_flags & MEGAFAUNA_SPAWN_ALLOWED) && length(megafauna_spawn_list)
-
-	for(var/i in turfs) //Go through all the turfs and generate them
-		var/turf/gen_turf = i
+	for(var/turf/gen_turf as anything in turfs) //Go through all the turfs and generate them
 
 		var/closed = string_gen[world.maxx * (gen_turf.y - 1) + gen_turf.x] != "0"
 		var/turf/new_turf = pick(closed ? closed_turf_types : open_turf_types)
@@ -162,8 +164,8 @@
 		var/datum/biome/selected_biome
 
 		// Here comes the meat of the biome code.
-		var/drift_x = clamp((gen_turf.x + rand(-BIOME_RANDOM_SQUARE_DRIFT, BIOME_RANDOM_SQUARE_DRIFT)), 1, world.maxx) // / perlin_zoom
-		var/drift_y = clamp((gen_turf.y + rand(-BIOME_RANDOM_SQUARE_DRIFT, BIOME_RANDOM_SQUARE_DRIFT)), 2, world.maxy) // / perlin_zoom
+		var/drift_x = clamp(((gen_turf.x + rand(-BIOME_RANDOM_SQUARE_DRIFT, BIOME_RANDOM_SQUARE_DRIFT)) / perlin_zoom), 1, world.maxx)
+		var/drift_y = clamp(((gen_turf.y + rand(-BIOME_RANDOM_SQUARE_DRIFT, BIOME_RANDOM_SQUARE_DRIFT)) / perlin_zoom), 2, world.maxy)
 
 		// Where we go in the generated string (generated outside of the loop for s p e e d)
 		var/coordinate = world.maxx * (drift_y - 1) + drift_x
@@ -223,35 +225,40 @@
 		// If we've spawned something yet
 		var/spawned_something = FALSE
 
-		///Spawning isn't done in procs to save on overhead on the 60k turfs we're going through.
-		//FLORA SPAWNING HERE
-		if(flora_allowed && prob(flora_spawn_chance))
-			var/flora_type = pick(flora_spawn_list)
-			new flora_type(new_turf)
-			spawned_something = TRUE
+		if(!(target_turf.turf_flags & TURF_BLOCKS_POPULATE_TERRAIN_FLORAFEATURES))
+			///Spawning isn't done in procs to save on overhead on the 60k turfs we're going through.
+			//FLORA SPAWNING HERE
+			if(flora_allowed && prob(flora_spawn_chance))
+				var/flora_type = pick(flora_spawn_list)
+				new flora_type(target_turf)
+				spawned_something = TRUE
 
-		//FEATURE SPAWNING HERE
-		if(feature_allowed && prob(feature_spawn_chance))
-			var/can_spawn = TRUE
+			//FEATURE SPAWNING HERE
+			//we may have generated something from the flora list on the target turf, so let's not place
+			//a feature here if that's the case (because it would look stupid)
+			if(feature_allowed && !spawned_something && prob(feature_spawn_chance))
+				var/can_spawn = TRUE
 
-			var/atom/picked_feature = pick(feature_spawn_list)
+				var/atom/picked_feature = pick(feature_spawn_list)
 
-			for(var/obj/structure/existing_feature in range(7, new_turf))
-				if(istype(existing_feature, picked_feature))
-					can_spawn = FALSE
-					break
+				for(var/obj/structure/existing_feature in range(7, target_turf))
+					if(istype(existing_feature, picked_feature))
+						can_spawn = FALSE
+						break
 
-			if(can_spawn)
-				new picked_feature(new_turf)
-				spawned_something = TRUE
+				if(can_spawn)
+					new picked_feature(target_turf)
+					spawned_something = TRUE
 
 		//MOB SPAWNING HERE
 		if(mobs_allowed && !spawned_something && prob(mob_spawn_chance))
 			var/atom/picked_mob = pick(mob_spawn_list)
+			var/is_megafauna = FALSE
 
 			if(picked_mob == SPAWN_MEGAFAUNA)
 				if(megas_allowed) //this is danger. it's boss time.
 					picked_mob = pick(megafauna_spawn_list)
+					is_megafauna = TRUE
 				else //this is not danger, don't spawn a boss, spawn something else
 					picked_mob = pick(mob_spawn_no_mega_list) //What if we used 100% of the brain...and did something (slightly) less shit than a while loop?
 
@@ -259,19 +266,22 @@
 
 			// prevents tendrils spawning in each other's collapse range
 			if(ispath(picked_mob, /obj/structure/spawner/lavaland))
-				for(var/obj/structure/spawner/lavaland/spawn_blocker in range(2, new_turf))
+				for(var/obj/structure/spawner/lavaland/spawn_blocker in range(2, target_turf))
 					can_spawn = FALSE
 					break
 			// if the random is not a tendril (hopefully meaning it is a mob), avoid spawning if there's another one within 12 tiles
 			else
-				var/list/things_in_range = range(12, new_turf)
+				var/list/things_in_range = range(12, target_turf)
 				for(var/mob/living/mob_blocker in things_in_range)
 					if(ismining(mob_blocker))
 						can_spawn = FALSE
 						break
+				// Also block spawns if there's a random lavaland mob spawner nearby and it's not a mega
+				if(!is_megafauna)
+					can_spawn = can_spawn && !(locate(/obj/effect/spawner/random/lavaland_mob) in things_in_range)
 			//if there's a megafauna within standard view don't spawn anything at all (This isn't really consistent, I don't know why we do this. you do you tho)
 			if(can_spawn)
-				for(var/mob/living/simple_animal/hostile/megafauna/found_fauna in range(7, new_turf))
+				for(var/mob/living/simple_animal/hostile/megafauna/found_fauna in range(7, target_turf))
 					can_spawn = FALSE
 					break
 
@@ -280,11 +290,11 @@
 					weighted_megafauna_spawn_list.Remove(picked_mob)
 					megafauna_spawn_list = expand_weights(weighted_megafauna_spawn_list)
 					megas_allowed = megas_allowed && length(megafauna_spawn_list)
-				new picked_mob(new_turf)
+				new picked_mob(target_turf)
 				spawned_something = TRUE
 		CHECK_TICK
 
-	var/message = "[name] finished in [(REALTIMEOFDAY - start_time)/10]s!"
+	var/message = "[name] terrain population finished in [(REALTIMEOFDAY - start_time)/10]s!"
 	to_chat(world, span_boldannounce("[message]"))
 	log_world(message)
 
diff --git a/code/game/objects/structures/flora.dm b/code/game/objects/structures/flora.dm
index 0ddfcf235eee..0ed9d046ecde 100644
--- a/code/game/objects/structures/flora.dm
+++ b/code/game/objects/structures/flora.dm
@@ -299,7 +299,7 @@
 	. = ..()
 	var/turf/my_turf = get_turf(src)
 	playsound(my_turf, 'sound/effects/meteorimpact.ogg', 100 , FALSE, FALSE)
-	var/obj/structure/flora/tree/stump/new_stump = new(my_turf)
+	var/obj/structure/flora/tree/stump/new_stump = new stump_type(my_turf)
 	new_stump.name = "[name] stump"
 
 /obj/structure/flora/tree/uproot(mob/living/user)
diff --git a/code/modules/procedural_mapping/mapGenerator.dm b/code/modules/procedural_mapping/mapGenerator.dm
index 4a79ad4c3059..2adbc8601943 100644
--- a/code/modules/procedural_mapping/mapGenerator.dm
+++ b/code/modules/procedural_mapping/mapGenerator.dm
@@ -14,6 +14,10 @@
 		buildmode_name = copytext_char("[type]", 20) // / d a t u m / m a p g e n e r a t o r / = 20 characters.
 	initialiseModules()
 
+/// Populate terrain with flora, fauna, features and basically everything that isn't a turf.
+/datum/map_generator/proc/populate_terrain(list/turfs, area/generate_in)
+	return
+
 //Defines the region the map represents, sets map
 //Returns the map
 /datum/map_generator/proc/defineRegion(turf/Start, turf/End, replace = 0)
diff --git a/monkestation/code/modules/liquids/ocean_generator.dm b/monkestation/code/modules/liquids/ocean_generator.dm
index 46db1b9f09c1..7f6161d78188 100644
--- a/monkestation/code/modules/liquids/ocean_generator.dm
+++ b/monkestation/code/modules/liquids/ocean_generator.dm
@@ -107,7 +107,7 @@
 	flora_spawn_list = null
 
 	///2D list of all biomes based on heat and humidity combos.
-	var/list/possible_biomes = list(
+	possible_biomes = list(
 	BIOME_LOW_HEAT = list(
 		BIOME_LOW_HUMIDITY = /datum/biome/ocean_sand/above,
 		BIOME_LOWMEDIUM_HUMIDITY = /datum/biome/ocean_sand_flora/above,
@@ -134,7 +134,7 @@
 		)
 	)
 	///Used to select "zoom" level into the perlin noise, higher numbers result in slower transitions
-	var/perlin_zoom = 65
+	perlin_zoom = 65
 
 
 /datum/map_generator/cave_generator/trench/generate_terrain(list/turfs, area/generate_in)
diff --git a/monkestation/code/modules/map_gen_expansions/README.md b/monkestation/code/modules/map_gen_expansions/README.md
new file mode 100644
index 000000000000..d9def091615f
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/README.md
@@ -0,0 +1,8 @@
+## Title: MapGen Expansions
+
+MODULE ID: MAPEXPANSIONS
+
+### Credits:
+
+Credits to SableSteel (sable.steel on Discord, thlumyn on Github) for the sprites
+Credits to GoldenAlpharex for the biome generation and other code
diff --git a/monkestation/code/modules/map_gen_expansions/_basemapping.dm b/monkestation/code/modules/map_gen_expansions/_basemapping.dm
new file mode 100644
index 000000000000..1ddefd02b734
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/_basemapping.dm
@@ -0,0 +1,8 @@
+/// Returns true if the map we're playing on is on a planet, but it DOES have space access.
+/datum/controller/subsystem/mapping/proc/is_planetary_with_space()
+	return config.planetary && config.allow_space_when_planetary
+
+
+/datum/map_config
+	/// Are we allowing space even if we're planetary?
+	var/allow_space_when_planetary = FALSE
diff --git a/monkestation/code/modules/map_gen_expansions/ai/behaviours/hiding.dm b/monkestation/code/modules/map_gen_expansions/ai/behaviours/hiding.dm
new file mode 100644
index 000000000000..d4b2150909b5
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/ai/behaviours/hiding.dm
@@ -0,0 +1,59 @@
+/// This behavior is to run any code that needs to be ran when the mob is going
+/// into hiding, or coming out from hiding.
+/datum/ai_behavior/toggle_hiding
+	/// The blackboard cooldown key to check before we can hide. Only here
+	/// to avoid copy-paste in other subtrees/behaviors, should only be SET,
+	/// not READ here.
+	var/cooldown_before_hiding_key = BB_HIDING_COOLDOWN_BEFORE_HIDING
+
+
+/datum/ai_behavior/toggle_hiding/setup(datum/ai_controller/controller, ...)
+	. = ..()
+
+	if(!controller.blackboard[BB_HIDING_AGGRO_RANGE_NOT_HIDING])
+		controller.set_blackboard_key(BB_HIDING_AGGRO_RANGE_NOT_HIDING, controller.blackboard[BB_AGGRO_RANGE])
+
+
+/datum/ai_behavior/toggle_hiding/perform(seconds_per_tick, datum/ai_controller/controller, now_hiding)
+	var/mob/living/basic/hiding_pawn = controller.pawn
+
+	if(!istype(hiding_pawn))
+		finish_action(controller, FALSE)
+		return
+
+	var/mob/living/living_pawn = controller.pawn
+
+	// Let's add some checks if we're trying to hide.
+	if(now_hiding)
+		// We can't hide if we can't move properly, or if we don't have any valid hiding locations.
+		if(!(living_pawn.mobility_flags & MOBILITY_MOVE) || !isturf(living_pawn.loc) || living_pawn.pulledby || !islist(controller.blackboard[BB_HIDING_CAN_HIDE_ON]))
+			finish_action(controller, FALSE)
+			return
+
+		// We can't hide if we don't match the proper turf type we need to hide onto.
+		if(!controller.blackboard[BB_HIDING_CAN_HIDE_ON][living_pawn.loc.type])
+			finish_action(controller, FALSE)
+			return
+
+	var/hiding_status_changed = controller.blackboard[BB_HIDING_HIDDEN] != now_hiding
+
+	if(!hiding_status_changed)
+		finish_action(controller, TRUE)
+		return
+
+	controller.set_blackboard_key(BB_HIDING_HIDDEN, now_hiding)
+	SEND_SIGNAL(living_pawn, COMSIG_MOVABLE_TOGGLE_HIDING, now_hiding, TRUE)
+
+	var/new_vision_range = now_hiding ? controller.blackboard[BB_HIDING_AGGRO_RANGE] || DEFAULT_HIDING_AGGRO_RANGE : controller.blackboard[BB_HIDING_AGGRO_RANGE_NOT_HIDING]
+
+	if(!now_hiding)
+		var/cooldown_minimum = controller.blackboard[BB_HIDING_COOLDOWN_MINIMUM] || 1 MINUTES
+		var/cooldown_maximum = controller.blackboard[BB_HIDING_COOLDOWN_MAXIMUM] || 3 MINUTES
+		var/new_cooldown = world.time + rand(cooldown_minimum, cooldown_maximum)
+		controller.set_blackboard_key(cooldown_before_hiding_key, new_cooldown)
+
+	controller.set_blackboard_key(BB_AGGRO_RANGE, new_vision_range)
+
+	finish_action(controller, TRUE)
+	return
+
diff --git a/monkestation/code/modules/map_gen_expansions/ai/idle_behaviours.dm b/monkestation/code/modules/map_gen_expansions/ai/idle_behaviours.dm
new file mode 100644
index 000000000000..208ff5458b9a
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/ai/idle_behaviours.dm
@@ -0,0 +1,9 @@
+/datum/idle_behavior/idle_random_walk/hide
+
+
+/datum/idle_behavior/idle_random_walk/hide/perform_idle_behavior(seconds_per_tick, datum/ai_controller/controller)
+	// You can't move when you're hidden.
+	if(controller.blackboard[BB_HIDING_HIDDEN])
+		return FALSE
+
+	return ..()
diff --git a/monkestation/code/modules/map_gen_expansions/ai/subtree/find_target_not_hiding.dm b/monkestation/code/modules/map_gen_expansions/ai/subtree/find_target_not_hiding.dm
new file mode 100644
index 000000000000..cc84e61f0424
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/ai/subtree/find_target_not_hiding.dm
@@ -0,0 +1,9 @@
+// Prevents finding a target if hiding.
+/datum/ai_planning_subtree/simple_find_target/not_while_hiding
+	operational_datums = list(/datum/element/can_hide)
+
+/datum/ai_planning_subtree/simple_find_target/not_while_hiding/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
+	if(controller.blackboard[BB_HIDING_HIDDEN])
+		return
+
+	return ..()
diff --git a/monkestation/code/modules/map_gen_expansions/ai/subtree/hiding.dm b/monkestation/code/modules/map_gen_expansions/ai/subtree/hiding.dm
new file mode 100644
index 000000000000..7c02f2945932
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/ai/subtree/hiding.dm
@@ -0,0 +1,57 @@
+/// By how much should the time until they start hiding again be multiplied with.
+#define START_HIDING_COOLDOWN_COEFFICIENT 0.1
+
+/// This subtree causes the mob to go into hiding after a random duration
+/// since the last time they went into hiding.
+/datum/ai_planning_subtree/random_hiding
+	operational_datums = list(/datum/element/can_hide)
+	/// The blackboard cooldown key to check before we hide.
+	var/cooldown_before_hiding_key = BB_HIDING_COOLDOWN_BEFORE_HIDING
+	/// The blackboard cooldown key to check before check if we can should stop hiding.
+	var/cooldown_before_stop_hiding_key = BB_HIDING_COOLDOWN_BEFORE_STOP_HIDING
+	/// The blackboard target key to check, that will force a cooldown reset
+	/// if the cooldown is below the minimum cooldown duration.
+	var/target_key = BB_BASIC_MOB_CURRENT_TARGET
+
+
+/datum/ai_planning_subtree/random_hiding/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
+	var/cooldown_minimum = controller.blackboard[BB_HIDING_COOLDOWN_MINIMUM] || 1 MINUTES
+	var/cooldown_maximum = controller.blackboard[BB_HIDING_COOLDOWN_MAXIMUM] || 3 MINUTES
+
+	if(controller.blackboard[BB_HIDING_HIDDEN])
+		// We can't stop hiding randomly until this cooldown is over.
+		if(controller.blackboard[cooldown_before_stop_hiding_key] && controller.blackboard[cooldown_before_stop_hiding_key] > world.time)
+			return
+
+		var/chance_to_stop_hiding = controller.blackboard[BB_HIDING_RANDOM_STOP_HIDING_CHANCE] || DEFAULT_RANDOM_STOP_HIDING_CHANCE
+		if(SPT_PROB(chance_to_stop_hiding, seconds_per_tick))
+			controller.queue_behavior(/datum/ai_behavior/toggle_hiding, FALSE)
+			var/new_cooldown = world.time + rand(cooldown_minimum, cooldown_maximum) * START_HIDING_COOLDOWN_COEFFICIENT
+			controller.set_blackboard_key(cooldown_before_hiding_key, new_cooldown)
+
+			return SUBTREE_RETURN_FINISH_PLANNING
+
+		return // We don't want to do anything else if we're currently hiding.
+
+	// If we have a target, we possibly want to reset the cooldown.
+	if(controller.blackboard[target_key])
+		// If the cooldown we have is more than the minimum cooldown, don't do anything.
+		if(controller.blackboard[cooldown_before_hiding_key] && controller.blackboard[cooldown_before_hiding_key] - world.time >= cooldown_minimum)
+			return
+
+		// Let's just reset the cooldown, now, then.
+		var/new_cooldown = world.time + rand(cooldown_minimum, cooldown_maximum)
+		controller.set_blackboard_key(cooldown_before_hiding_key, new_cooldown)
+
+		return
+
+	// If we can't hide yet, we do nothing.
+	if(controller.blackboard[cooldown_before_hiding_key] && controller.blackboard[cooldown_before_hiding_key] > world.time)
+		return
+
+	// We can hide, so let's do just that!
+	controller.queue_behavior(/datum/ai_behavior/toggle_hiding, TRUE)
+	var/new_cooldown = world.time + rand(cooldown_minimum, cooldown_maximum)
+	controller.set_blackboard_key(cooldown_before_stop_hiding_key, new_cooldown)
+
+	return SUBTREE_RETURN_FINISH_PLANNING
diff --git a/monkestation/code/modules/map_gen_expansions/ai/subtree/retaliate_target.dm b/monkestation/code/modules/map_gen_expansions/ai/subtree/retaliate_target.dm
new file mode 100644
index 000000000000..d2fc490027b7
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/ai/subtree/retaliate_target.dm
@@ -0,0 +1,19 @@
+// This is to ensure retaliation breaks the "hiding" state if a target is found.
+/datum/ai_planning_subtree/target_retaliate/check_faction/stop_hiding
+	operational_datums = list(/datum/element/can_hide)
+
+
+/datum/ai_planning_subtree/target_retaliate/check_faction/stop_hiding/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
+	controller.queue_behavior(/datum/ai_behavior/target_from_retaliate_list/stop_hiding, BB_BASIC_MOB_RETALIATE_LIST, target_key, targeting_strategy_key, hiding_place_key, check_faction)
+
+
+// This is to ensure retaliation breaks the "hiding" state if a target is found.
+/datum/ai_behavior/target_from_retaliate_list/stop_hiding
+
+
+/datum/ai_behavior/target_from_retaliate_list/stop_hiding/finish_action(datum/ai_controller/controller, succeeded, shitlist_key, target_key, targeting_strategy_key, hiding_location_key, check_faction)
+	. = ..()
+	if(!controller.blackboard[BB_HIDING_HIDDEN] || !succeeded)
+		return
+
+	controller.queue_behavior(/datum/ai_behavior/toggle_hiding, FALSE)
diff --git a/monkestation/code/modules/map_gen_expansions/ai/subtree/stop_hiding_if_target.dm b/monkestation/code/modules/map_gen_expansions/ai/subtree/stop_hiding_if_target.dm
new file mode 100644
index 000000000000..afc5d566418c
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/ai/subtree/stop_hiding_if_target.dm
@@ -0,0 +1,12 @@
+
+/// This subtree ensures that the mob gets out from hiding if they have a target.
+/datum/ai_planning_subtree/stop_hiding_if_target
+	operational_datums = list(/datum/element/can_hide, /datum/element/can_hide/basic)
+	/// Blackboard key where we check if there's currently a target.
+	var/target_key = BB_BASIC_MOB_CURRENT_TARGET
+
+
+/datum/ai_planning_subtree/stop_hiding_if_target/SelectBehaviors(datum/ai_controller/controller, seconds_per_tick)
+	if(controller.blackboard[BB_BASIC_MOB_CURRENT_TARGET] && controller.blackboard[BB_HIDING_HIDDEN])
+		controller.queue_behavior(/datum/ai_behavior/toggle_hiding, FALSE)
+
diff --git a/monkestation/code/modules/map_gen_expansions/areas.dm b/monkestation/code/modules/map_gen_expansions/areas.dm
new file mode 100644
index 000000000000..e47fd6402022
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/areas.dm
@@ -0,0 +1,34 @@
+/area/forestplanet
+	icon = 'icons/area/areas_station.dmi'
+	icon_state = "mining"
+	has_gravity = STANDARD_GRAVITY
+	flags_1 = NONE
+	area_flags = UNIQUE_AREA | FLORA_ALLOWED
+	//ambience_index = AMBIENCE_ICEMOON
+	sound_environment = SOUND_AREA_ICEMOON
+	ambient_buzz = 'sound/ambience/magma.ogg'
+	name = "Forest Planet"
+	icon_state = "explored"
+	always_unpowered = TRUE
+	power_environ = FALSE
+	power_equip = FALSE
+	power_light = FALSE
+	requires_power = TRUE
+	min_ambience_cooldown = 70 SECONDS
+	max_ambience_cooldown = 220 SECONDS
+
+/area/forestplanet/outdoors // parent that defines if something is on the exterior of the station.
+	name = "Woodlands"
+	outdoors = TRUE
+
+/area/forestplanet/outdoors/nospawn
+
+/area/forestplanet/outdoors/unexplored
+	icon_state = "unexplored"
+	area_flags = UNIQUE_AREA | FLORA_ALLOWED | MOB_SPAWN_ALLOWED | CAVES_ALLOWED
+	map_generator = /datum/map_generator/cave_generator/forest
+
+/area/forestplanet/outdoors/unexplored/deep
+	name = "Mushroom Caves"
+	map_generator = /datum/map_generator/cave_generator/forest/mushroom
+
diff --git a/monkestation/code/modules/map_gen_expansions/elements/can_hide.dm b/monkestation/code/modules/map_gen_expansions/elements/can_hide.dm
new file mode 100644
index 000000000000..8187378a15ba
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/elements/can_hide.dm
@@ -0,0 +1,56 @@
+/// This element serves to allow movables to hide when they receive the
+/// `COMSIG_MOVABLE_TOGGLE_HIDING` signal. Does NOT do any form of checking,
+/// it's on the caller to check if they should be calling this or not.
+/datum/element/can_hide
+	element_flags = ELEMENT_DETACH_ON_HOST_DESTROY
+
+
+/datum/element/can_hide/Attach(atom/movable/target)
+	. = ..()
+
+	if(!istype(target))
+		return ELEMENT_INCOMPATIBLE
+
+	RegisterSignal(target, COMSIG_MOVABLE_TOGGLE_HIDING, PROC_REF(on_toggle_hiding))
+	ADD_TRAIT(target, TRAIT_SUBTREE_REQUIRED_OPERATIONAL_DATUM, type)
+
+
+/datum/element/can_hide/Detach(datum/source, ...)
+	. = ..()
+
+	UnregisterSignal(source, COMSIG_MOVABLE_TOGGLE_HIDING)
+
+
+/**
+ * Handles toggling whatever needs to be toggled on the target in when they
+ * hide or come back from hiding. Does NOT check if they were already in the same
+ * state, so check that yourself.
+ */
+/datum/element/can_hide/proc/on_toggle_hiding(atom/movable/target, hiding, play_feedback = TRUE)
+	SIGNAL_HANDLER
+
+	target.pass_flags_self = hiding ? PASSSTRUCTURE : initial(target.pass_flags_self)
+	target.icon_state = "[target.base_icon_state][hiding ? "_hidden" : ""]"
+
+	if(play_feedback)
+		playsound(target, 'sound/effects/bodyfall1.ogg', 50, TRUE)
+		new /obj/effect/temp_visual/mook_dust(get_turf(target))
+
+	target.update_appearance()
+
+/// Like datum/element/can_hide, but for basic mobs.
+/datum/element/can_hide/basic
+
+// Contains an additional parameter, can_hide_types, to tell the basic mob AI subroutine what types of turfs it can hide onto.
+/datum/element/can_hide/basic/Attach(datum/target, list/turf/can_hide_types)
+	var/mob/living/basic/basic_target = target
+	if(!istype(basic_target))
+		return ELEMENT_INCOMPATIBLE
+
+	. = ..()
+
+	if(. == ELEMENT_INCOMPATIBLE)
+		return
+
+	basic_target.ai_controller?.set_blackboard_key(BB_HIDING_CAN_HIDE_ON, typecacheof(can_hide_types))
+
diff --git a/monkestation/code/modules/map_gen_expansions/forest/atmosphere.dm b/monkestation/code/modules/map_gen_expansions/forest/atmosphere.dm
new file mode 100644
index 000000000000..79ae14fc521f
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/forest/atmosphere.dm
@@ -0,0 +1,23 @@
+
+/datum/atmosphere/forest
+	id = FOREST_DEFAULT_ATMOS
+
+	base_gases = list(
+		/datum/gas/oxygen=5,
+		/datum/gas/nitrogen=10,
+	)
+	normal_gases = list(
+		/datum/gas/oxygen=10,
+		/datum/gas/nitrogen=10,
+		/datum/gas/bz=1.2,
+	)
+	restricted_gases = list(
+		/datum/gas/water_vapor=0.1,
+	)
+	restricted_chance = 20
+
+	minimum_pressure = HAZARD_LOW_PRESSURE + 10
+	maximum_pressure = LAVALAND_EQUIPMENT_EFFECT_PRESSURE - 1
+
+	minimum_temp = BODYTEMP_COLD_DAMAGE_LIMIT + 4
+	maximum_temp = 350
diff --git a/monkestation/code/modules/map_gen_expansions/forest/generator.dm b/monkestation/code/modules/map_gen_expansions/forest/generator.dm
new file mode 100644
index 000000000000..a78e735e211f
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/forest/generator.dm
@@ -0,0 +1,36 @@
+
+/datum/map_generator/cave_generator/forest
+	weighted_open_turf_types = list(/turf/open/misc/asteroid/forest = 1)
+	weighted_closed_turf_types = list(/turf/closed/mineral/random/forest = 1)
+	flora_spawn_chance = 35
+	initial_closed_chance = 53
+	birth_limit = 5
+	death_limit = 4
+	smoothing_iterations = 10
+
+	weighted_mob_spawn_list = list(
+		/mob/living/basic/deer/mining = 50,
+		/mob/living/basic/mining/megadeer = 15,
+		/mob/living/basic/mining/goldgrub = 1,
+	)
+
+	weighted_flora_spawn_list = list(
+		/obj/structure/flora/ash/fireblossom = 2,
+		/obj/structure/flora/grass/jungle/a/style_random = 15,
+		/obj/structure/flora/grass/jungle/b/style_random = 30,
+		/obj/structure/flora/bush/jungle/a/style_random = 5,
+		/obj/structure/flora/bush/jungle/b/style_random = 5,
+		/obj/structure/flora/bush/jungle/c/style_random = 5,
+		/obj/structure/flora/rock/pile/jungle/style_random = 3,
+		/obj/structure/flora/rock/pile/jungle/large/style_random = 1,
+		/obj/structure/flora/tree/jungle/style_random = 7,
+		/obj/structure/flora/tree/jungle/small/style_random = 3,
+	)
+	///Note that this spawn list is also in the lavaland generator
+	weighted_feature_spawn_list = list(
+		/obj/structure/geyser/hollowwater = 10,
+		/obj/structure/geyser/plasma_oxide = 10,
+		/obj/structure/geyser/protozine = 10,
+		/obj/structure/geyser/random = 2,
+		/obj/structure/geyser/wittel = 10,
+	)
diff --git a/monkestation/code/modules/map_gen_expansions/forest/mobs/deer.dm b/monkestation/code/modules/map_gen_expansions/forest/mobs/deer.dm
new file mode 100644
index 000000000000..6db0ecda7f92
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/forest/mobs/deer.dm
@@ -0,0 +1,3 @@
+/mob/living/basic/deer/mining
+	desc = "A common deer, used to living alongside monsters after generations on this planet."
+	faction = list("mining")
diff --git a/monkestation/code/modules/map_gen_expansions/forest/mobs/megadeer.dm b/monkestation/code/modules/map_gen_expansions/forest/mobs/megadeer.dm
new file mode 100644
index 000000000000..1108128bef4d
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/forest/mobs/megadeer.dm
@@ -0,0 +1,91 @@
+/mob/living/basic/mining/megadeer
+	name = "megadeer"
+	desc = "The descendants of the common deer, turned into angry beasts by the harshness of the land."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/newfauna_wide.dmi'
+	icon_state = "megadeer"
+	icon_living = "megadeer"
+	icon_dead = "megadeer_dead"
+	pixel_x = -12
+	base_pixel_x = -12
+	mob_biotypes = MOB_ORGANIC|MOB_BEAST
+	mouse_opacity = MOUSE_OPACITY_ICON
+	speak_emote = list("flutes")
+
+	butcher_results = list(
+		/obj/item/food/meat/slab = 2,
+		/obj/item/stack/sheet/sinew/deer = 2,
+		/obj/item/stack/sheet/bone = 2
+	)
+	crusher_loot = /obj/item/crusher_trophy/deer_fur
+
+	maxHealth = 180
+	health = 180
+	obj_damage = 15
+	melee_damage_lower = 15
+	melee_damage_upper = 15
+	attack_vis_effect = ATTACK_EFFECT_BITE
+	melee_attack_cooldown = 1.2 SECONDS
+
+	attack_verb_continuous = "bites"
+	attack_verb_simple = "bite"
+	death_message = "lets out a fluting cry and collapses."
+
+	attack_sound = 'sound/weapons/bite.ogg'
+	move_force = MOVE_FORCE_WEAK
+	move_resist = MOVE_FORCE_WEAK
+	pull_force = MOVE_FORCE_WEAK
+
+	ai_controller = /datum/ai_controller/basic_controller/megadeer
+
+	var/can_tame = FALSE
+
+/mob/living/basic/mining/megadeer/Initialize(mapload)
+	. = ..()
+
+	AddElement(/datum/element/footstep, FOOTSTEP_MOB_CLAW)
+	AddElement(/datum/element/ai_flee_while_injured)
+	AddElement(/datum/element/ai_retaliate)
+	AddComponent(/datum/component/basic_mob_ability_telegraph)
+	AddComponent(/datum/component/basic_mob_attack_telegraph, telegraph_duration = 0.6 SECONDS)
+
+/obj/item/crusher_trophy/deer_fur
+	name = "deer fur"
+	desc = "It's fur from a mega deer."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/misc.dmi'
+	icon_state = "deer_fur"
+	denied_type = /obj/item/crusher_trophy/deer_fur
+
+/obj/item/crusher_trophy/deer_fur/effect_desc()
+	return "mark detonation to gain a slight speed boost temporarily"
+
+/obj/item/crusher_trophy/deer_fur/on_mark_detonation(mob/living/target, mob/living/user)
+	user.apply_status_effect(/datum/status_effect/speed_boost, 1 SECONDS)
+
+//sinew re-flavor for megadeers
+/obj/item/stack/sheet/sinew/deer
+	name = "deer sinew"
+	singular_name = "deer sinew"
+	merge_type = /obj/item/stack/sheet/sinew/deer
+
+
+/datum/ai_controller/basic_controller/megadeer
+	blackboard = list(
+		BB_TARGETING_STRATEGY = /datum/targeting_strategy/basic/allow_items,
+		BB_PET_TARGETING_STRATEGY = /datum/targeting_strategy/basic/not_friends,
+		BB_BASIC_MOB_FLEE_DISTANCE = 25,
+		BB_VISION_RANGE = 9,
+		BB_TARGET_MINIMUM_STAT = HARD_CRIT,
+	)
+
+	ai_movement = /datum/ai_movement/basic_avoidance
+	idle_behavior = /datum/idle_behavior/idle_random_walk
+
+	planning_subtrees = list(
+		/datum/ai_planning_subtree/pet_planning,
+		/datum/ai_planning_subtree/simple_find_nearest_target_to_flee,
+		/datum/ai_planning_subtree/flee_target,
+		/datum/ai_planning_subtree/target_retaliate/check_faction,
+		/datum/ai_planning_subtree/simple_find_target,
+		/datum/ai_planning_subtree/attack_obstacle_in_path,
+		/datum/ai_planning_subtree/basic_melee_attack_subtree,
+	)
diff --git a/monkestation/code/modules/map_gen_expansions/icons/floors.dmi b/monkestation/code/modules/map_gen_expansions/icons/floors.dmi
new file mode 100644
index 000000000000..286374d2ecb6
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diff --git a/monkestation/code/modules/map_gen_expansions/icons/misc.dmi b/monkestation/code/modules/map_gen_expansions/icons/misc.dmi
new file mode 100644
index 000000000000..24b3ac3a8d5c
Binary files /dev/null and b/monkestation/code/modules/map_gen_expansions/icons/misc.dmi differ
diff --git a/monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi b/monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi
new file mode 100644
index 000000000000..be6aa52584a6
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diff --git a/monkestation/code/modules/map_gen_expansions/icons/mushroomtrees.dmi b/monkestation/code/modules/map_gen_expansions/icons/mushroomtrees.dmi
new file mode 100644
index 000000000000..d59250a58378
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diff --git a/monkestation/code/modules/map_gen_expansions/icons/newfauna_wide.dmi b/monkestation/code/modules/map_gen_expansions/icons/newfauna_wide.dmi
new file mode 100644
index 000000000000..7aec3a722c25
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diff --git a/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom.dmi b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom.dmi
new file mode 100644
index 000000000000..b67fe036d1a9
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diff --git a/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_blue.dmi b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_blue.dmi
new file mode 100644
index 000000000000..d2c46a2e2d68
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diff --git a/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_green.dmi b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_green.dmi
new file mode 100644
index 000000000000..c963322f4ead
Binary files /dev/null and b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_green.dmi differ
diff --git a/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest.dmi b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest.dmi
new file mode 100644
index 000000000000..38a62425429c
Binary files /dev/null and b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest.dmi differ
diff --git a/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest_mask.dmi b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest_mask.dmi
new file mode 100644
index 000000000000..b8fa24c78c87
Binary files /dev/null and b/monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest_mask.dmi differ
diff --git a/monkestation/code/modules/map_gen_expansions/mushroom/flora.dm b/monkestation/code/modules/map_gen_expansions/mushroom/flora.dm
new file mode 100644
index 000000000000..01c9a845eb79
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/mushroom/flora.dm
@@ -0,0 +1,213 @@
+
+#define LIGHT_FIRE_BLOSSOM 2.1
+
+/obj/structure/flora/tree
+	/// The type of stump to spawn when harvested.
+	var/stump_type = /obj/structure/flora/tree/stump
+
+/obj/structure/flora/tree/mushroom
+	name = "mushroom tree"
+	desc = "A large branching mushroom that seems to thrive under the planet's surface."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroomtrees.dmi'
+	icon_state = "tree1"
+	base_icon_state = "tree_dead1"
+	pixel_x = -48
+	pixel_y = -20
+	stump_type = /obj/structure/flora/tree/stump/mushroom
+
+/obj/structure/flora/tree/mushroom/reverse
+	icon_state = "tree2"
+	stump_type = /obj/structure/flora/tree/stump/mushroom/reverse
+
+/obj/structure/flora/tree/mushroom/blue
+	icon_state = "tree_blue1"
+
+/obj/structure/flora/tree/mushroom/blue/reverse
+	icon_state = "tree_blue2"
+	stump_type = /obj/structure/flora/tree/stump/mushroom/reverse
+
+/obj/structure/flora/tree/mushroom/green
+	icon_state = "tree_green1"
+
+/obj/structure/flora/tree/mushroom/green/reverse
+	icon_state = "tree_green2"
+	stump_type = /obj/structure/flora/tree/stump/mushroom/reverse
+
+/obj/structure/flora/tree/stump/mushroom
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroomtrees.dmi'
+	icon_state = "tree1_dead"
+	pixel_x = -48
+	pixel_y = -20
+
+/obj/structure/flora/tree/stump/mushroom/reverse
+	icon_state = "tree2_dead"
+
+/obj/structure/flora/ash/tall_shroom/colored
+	desc = "A number of large mushrooms, covered in a faint layer of what can only be spores."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "l_mushroom_red1"
+	base_icon_state = "l_mushroom_red"
+	number_of_variants = 1
+
+/obj/structure/flora/ash/tall_shroom/colored/blue
+	icon_state = "l_mushroom_blue1"
+	base_icon_state = "l_mushroom_blue"
+
+/obj/structure/flora/ash/tall_shroom/colored/green
+	icon_state = "l_mushroom_green1"
+	base_icon_state = "l_mushroom_green"
+
+/obj/structure/flora/ash/leaf_shroom/colored
+	desc = "A number of mushrooms, each of which surrounds a colorful sporangium with a number of leaf-like structures."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "s_mushroom_red1"
+	base_icon_state = "s_mushroom_red"
+	number_of_variants = 1
+
+/obj/structure/flora/ash/leaf_shroom/colored/blue
+	icon_state = "s_mushroom_blue1"
+	base_icon_state = "s_mushroom_blue"
+
+/obj/structure/flora/ash/leaf_shroom/colored/green
+	icon_state = "s_mushroom_green1"
+	base_icon_state = "s_mushroom_green"
+
+/obj/structure/flora/ash/cap_shroom/colored
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "r_mushroom_red1"
+	base_icon_state = "r_mushroom_red"
+	number_of_variants = 1
+
+/obj/structure/flora/ash/cap_shroom/colored/blue
+	icon_state = "r_mushroom_blue1"
+	base_icon_state = "r_mushroom_blue"
+
+/obj/structure/flora/ash/cap_shroom/colored/green
+	icon_state = "r_mushroom_green1"
+	base_icon_state = "r_mushroom_green"
+
+/obj/structure/flora/ash/stem_shroom/colored
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "t_mushroom_red1"
+	base_icon_state = "t_mushroom_red"
+
+/obj/structure/flora/ash/stem_shroom/colored/blue
+	icon_state = "t_mushroom_blue1"
+	base_icon_state = "t_mushroom_blue"
+
+/obj/structure/flora/ash/stem_shroom/colored/green
+	icon_state = "t_mushroom_green1"
+	base_icon_state = "t_mushroom_green"
+
+/obj/structure/flora/mushroom
+	name = "mushroom"
+	desc = "Some type of large mushroom... It looks suspicious."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "fake_stillcap_red"
+	flora_flags = FLORA_HERBAL
+
+/obj/structure/flora/mushroom/blue
+	icon_state = "fake_stillcap_blue"
+
+/obj/structure/flora/mushroom/green
+	icon_state = "fake_stillcap_green"
+
+/obj/structure/flora/ash/lightshroom
+	name = "lightshroom"
+	desc = "An odd glowing mushroom that grows in areas with underground liquid plasma springs."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "red_mushroom1"
+	base_icon_state = "red_mushroom"
+	light_outer_range = LIGHT_FIRE_BLOSSOM
+	light_power = LIGHT_FIRE_BLOSSOM
+	light_color = COLOR_RED_LIGHT
+	product_types = list(/obj/item/food/grown/ash_flora/lightshroom = 1)
+	harvested_name = "lightshroom stems"
+	harvested_desc = "A few lightshroom stems, missing their caps."
+	harvest_amount_high = 3
+	harvest_message_low = "You pluck a single, suitable mushroom."
+	harvest_message_med = "You pluck a number of mushrooms, leaving a few unsuitable ones."
+	harvest_message_high = "You pluck quite a lot of suitable mushrooms."
+	regrowth_time_low = 2500
+	regrowth_time_high = 4000
+	number_of_variants = 1
+
+/obj/structure/flora/ash/lightshroom/after_harvest()
+	set_light_power(LIGHT_RANGE_FIRE_BLOSSOM_HARVESTED)
+	set_light_range(LIGHT_POWER_FIRE_BLOSSOM_HARVESTED)
+	update_light()
+	return ..()
+
+/obj/structure/flora/ash/lightshroom/regrow()
+	set_light_power(initial(light_power))
+	set_light_range(initial(light_outer_range))
+	update_light()
+	return ..()
+
+/obj/structure/flora/ash/lightshroom/blue
+	icon_state = "blue_mushroom1"
+	base_icon_state = "blue_mushroom"
+	light_color = COLOR_BIOLUMINESCENCE_BLUE
+	product_types = list(/obj/item/food/grown/ash_flora/lightshroom/blue = 1)
+
+/obj/structure/flora/ash/lightshroom/green
+	icon_state = "green_mushroom1"
+	base_icon_state = "green_mushroom"
+	light_color = COLOR_BIOLUMINESCENCE_GREEN
+	product_types = list(/obj/item/food/grown/ash_flora/lightshroom/green = 1)
+
+/obj/item/food/grown/ash_flora/lightshroom
+	name = "red lightshroom"
+	desc = "A glowing mushroom."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "red_mushroom_grown"
+	seed = /obj/item/seeds/lavaland/lightshroom
+	wine_power = 40
+	special_desc_requirement = EXAMINE_CHECK_JOB
+	special_desc_jobs = list("Botanist")
+	special_desc = "This flora contains some healing properties, if you can filter out the radioactive toxins."
+
+/obj/item/food/grown/ash_flora/lightshroom/blue
+	name = "blue lightshroom"
+	icon_state = "blue_mushroom_grown"
+	seed = /obj/item/seeds/lavaland/lightshroom/blue
+
+/obj/item/food/grown/ash_flora/lightshroom/green
+	name = "green lightshroom"
+	icon_state = "green_mushroom_grown"
+	seed = /obj/item/seeds/lavaland/lightshroom/green
+
+/obj/item/seeds/lavaland/lightshroom
+	name = "pack of red lightshroom mycelium"
+	desc = "These seeds grow into colorful lightshrooms."
+	plantname = "Red Lightshroom"
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_state = "mycelium_red_mushroom"
+	species = "red_mushroom"
+	growthstages = 3
+	growing_icon = 'monkestation/code/modules/map_gen_expansions/icons/mushroom_flora.dmi'
+	icon_dead = "red_mushroom_dead"
+	product = /obj/item/food/grown/ash_flora/lightshroom
+	genes = list(/datum/plant_gene/trait/plant_type/fungal_metabolism, /datum/plant_gene/trait/glow/red)
+	reagents_add = list(/datum/reagent/consumable/nutriment = 0.04, /datum/reagent/consumable/vitfro = 0.04, /datum/reagent/uranium/radium = 0.04)
+	graft_gene = /datum/plant_gene/trait/plant_type/fungal_metabolism
+
+/obj/item/seeds/lavaland/lightshroom/blue
+	name = "pack of blue lightshroom mycelium"
+	plantname = "Blue Lightshroom"
+	icon_state = "mycelium_blue_mushroom"
+	species = "blue_mushroom"
+	icon_dead = "blue_mushroom_dead"
+	product = /obj/item/food/grown/ash_flora/lightshroom/blue
+	genes = list(/datum/plant_gene/trait/plant_type/fungal_metabolism, /datum/plant_gene/trait/glow/blue)
+
+/obj/item/seeds/lavaland/lightshroom/green
+	name = "pack of green lightshroom mycelium"
+	plantname = "Green Lightshroom"
+	icon_state = "mycelium_green_mushroom"
+	species = "green_mushroom"
+	icon_dead = "green_mushroom_dead"
+	product = /obj/item/food/grown/ash_flora/lightshroom/green
+	genes = list(/datum/plant_gene/trait/plant_type/fungal_metabolism, /datum/plant_gene/trait/glow/green)
+
+#undef LIGHT_FIRE_BLOSSOM
diff --git a/monkestation/code/modules/map_gen_expansions/mushroom/generator.dm b/monkestation/code/modules/map_gen_expansions/mushroom/generator.dm
new file mode 100644
index 000000000000..c276d76dea0a
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/mushroom/generator.dm
@@ -0,0 +1,109 @@
+
+/datum/map_generator/cave_generator/forest/mushroom
+	name = "Mushroom Cave Biome Generator"
+	weighted_open_turf_types = list(/turf/open/misc/dirt/forest = 3, /turf/open/misc/asteroid/forest/mushroom = 2)
+	weighted_closed_turf_types = list(/turf/closed/mineral/random/forest = 1)
+	initial_closed_chance = 53
+	birth_limit = 5
+	death_limit = 4
+	smoothing_iterations = 10
+
+	mob_spawn_chance = 0.25 //planning to increase this once we have custom mushroom mobs to increase diversity
+	flora_spawn_chance = 25
+
+	biome_accepted_turfs = list(
+		/turf/open/misc/asteroid/forest/mushroom = TRUE,
+	)
+	possible_biomes = list(
+		BIOME_LOW_HEAT = list(
+			BIOME_LOW_HUMIDITY = /datum/biome/mushroom_cave/blue,
+			BIOME_MEDIUM_HUMIDITY = /datum/biome/mushroom_cave,
+			BIOME_HIGH_HUMIDITY = /datum/biome/mushroom_cave/green,
+		),
+		BIOME_MEDIUM_HEAT = list(
+			BIOME_LOW_HUMIDITY = /datum/biome/mushroom_cave/green,
+			BIOME_MEDIUM_HUMIDITY = /datum/biome/mushroom_cave/blue,
+			BIOME_HIGH_HUMIDITY = /datum/biome/mushroom_cave,
+		),
+		BIOME_HIGH_HEAT = list(
+			BIOME_LOW_HUMIDITY = /datum/biome/mushroom_cave,
+			BIOME_MEDIUM_HUMIDITY = /datum/biome/mushroom_cave/green,
+			BIOME_HIGH_HUMIDITY = /datum/biome/mushroom_cave/blue,
+		)
+	)
+
+	weighted_mob_spawn_list = list(
+		/obj/effect/spawner/random/lavaland_mob/goliath = 1,
+	)
+	weighted_flora_spawn_list = list(
+		/obj/structure/flora/tree/mushroom = 4,
+		/obj/structure/flora/tree/mushroom/reverse = 4,
+		/obj/structure/flora/ash/lightshroom = 2,
+		/obj/structure/flora/mushroom = 2,
+		/obj/structure/flora/ash/cap_shroom/colored = 1,
+		/obj/structure/flora/ash/leaf_shroom/colored = 1,
+		/obj/structure/flora/ash/stem_shroom/colored = 1,
+		/obj/structure/flora/ash/tall_shroom/colored = 1,
+	)
+
+/datum/biome/mushroom_cave
+	turf_type = /turf/open/misc/asteroid/forest/mushroom
+	flora_density = 25
+	feature_density = 0.25
+	fauna_density = 1
+	flora_types = list(
+		/obj/structure/flora/tree/mushroom = 4,
+		/obj/structure/flora/tree/mushroom/reverse = 4,
+		/obj/structure/flora/ash/lightshroom = 2,
+		/obj/structure/flora/mushroom = 2,
+		/obj/structure/flora/ash/cap_shroom/colored = 1,
+		/obj/structure/flora/ash/leaf_shroom/colored = 1,
+		/obj/structure/flora/ash/stem_shroom/colored = 1,
+		/obj/structure/flora/ash/tall_shroom/colored = 1,
+	)
+	fauna_types = list(
+		/mob/living/basic/mining/stillcap = 3,
+	)
+	feature_types = list(
+		/obj/structure/geyser/hollowwater = 10,
+		/obj/structure/geyser/plasma_oxide = 10,
+		/obj/structure/geyser/protozine = 10,
+		/obj/structure/geyser/random = 2,
+		/obj/structure/geyser/wittel = 10,
+	)
+
+/datum/biome/mushroom_cave/blue
+	turf_type = /turf/open/misc/asteroid/forest/mushroom/blue
+	flora_density = 25
+	feature_density = 0.25
+	fauna_types = list(
+		/mob/living/basic/mining/stillcap/blue = 3,
+	)
+	flora_types = list(
+		/obj/structure/flora/tree/mushroom/blue = 4,
+		/obj/structure/flora/tree/mushroom/blue/reverse = 4,
+		/obj/structure/flora/ash/lightshroom/blue = 2,
+		/obj/structure/flora/mushroom/blue = 2,
+		/obj/structure/flora/ash/cap_shroom/colored/blue = 1,
+		/obj/structure/flora/ash/leaf_shroom/colored/blue = 1,
+		/obj/structure/flora/ash/stem_shroom/colored/blue = 1,
+		/obj/structure/flora/ash/tall_shroom/colored/blue = 1,
+	)
+
+/datum/biome/mushroom_cave/green
+	turf_type = /turf/open/misc/asteroid/forest/mushroom/green
+	flora_density = 25
+	feature_density = 0.25
+	fauna_types = list(
+		/mob/living/basic/mining/stillcap/green = 3,
+	)
+	flora_types = list(
+		/obj/structure/flora/tree/mushroom/green = 4,
+		/obj/structure/flora/tree/mushroom/green/reverse = 4,
+		/obj/structure/flora/ash/lightshroom/green = 2,
+		/obj/structure/flora/mushroom/green = 2,
+		/obj/structure/flora/ash/cap_shroom/colored/green = 1,
+		/obj/structure/flora/ash/leaf_shroom/colored/green = 1,
+		/obj/structure/flora/ash/stem_shroom/colored/green = 1,
+		/obj/structure/flora/ash/tall_shroom/colored/green = 1,
+	)
diff --git a/monkestation/code/modules/map_gen_expansions/mushroom/mobs/stillcaps.dm b/monkestation/code/modules/map_gen_expansions/mushroom/mobs/stillcaps.dm
new file mode 100644
index 000000000000..3d24d18a5a12
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/mushroom/mobs/stillcaps.dm
@@ -0,0 +1,100 @@
+
+/mob/living/basic/mining/stillcap
+	name = "stillcap"
+	desc = "A strange, elusive creature that always seems to come out of nowhere."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/newfauna_wide.dmi'
+	icon_state = "stillcap_red"
+	icon_living = "stillcap_red"
+	base_icon_state = "stillcap_red"
+	icon_dead = "stillcap_red_dead"
+	pixel_x = -12
+	base_pixel_x = -12
+	mob_biotypes = MOB_ORGANIC|MOB_BEAST
+
+	maxHealth = 180
+	health = 180
+	speed = 5
+	obj_damage = 15
+	melee_damage_lower = 15
+	melee_damage_upper = 15
+	attack_vis_effect = ATTACK_EFFECT_BITE
+	melee_attack_cooldown = 1.2 SECONDS
+
+	attack_verb_continuous = "bites"
+	attack_verb_simple = "bite"
+	death_message = "collapses in a muted thud."
+	pass_flags_self = PASSMOB
+
+	attack_sound = 'sound/weapons/bite.ogg'
+	move_force = MOVE_FORCE_WEAK
+	move_resist = MOVE_FORCE_WEAK
+	pull_force = MOVE_FORCE_WEAK
+	ai_controller = /datum/ai_controller/basic_controller/stillcap
+
+
+/mob/living/basic/mining/stillcap/Initialize(mapload)
+	. = ..()
+
+	AddElement(/datum/element/can_hide/basic, list(/turf/open/misc/asteroid/forest/mushroom))
+	AddElement(/datum/element/ai_flee_while_injured)
+	AddElement(/datum/element/ai_retaliate)
+	AddComponent(/datum/component/basic_mob_ability_telegraph)
+	AddComponent(/datum/component/basic_mob_attack_telegraph, telegraph_duration = 0.6 SECONDS)
+
+
+/mob/living/basic/mining/stillcap/red
+	name = "red stillcap"
+	desc = parent_type::desc + " This one appears to be red."
+	icon_state = "stillcap_red"
+	icon_living = "stillcap_red"
+	base_icon_state = "stillcap_red"
+	icon_dead = "stillcap_red_dead"
+
+
+/mob/living/basic/mining/stillcap/blue
+	name = "blue stillcap"
+	desc = parent_type::desc + " This one appears to be blue."
+	icon_state = "stillcap_blue"
+	icon_living = "stillcap_blue"
+	base_icon_state = "stillcap_blue"
+	icon_dead = "stillcap_blue_dead"
+
+
+/mob/living/basic/mining/stillcap/green
+	name = "green stillcap"
+	desc = parent_type::desc + " This one appears to be green."
+	icon_state = "stillcap_green"
+	icon_living = "stillcap_green"
+	base_icon_state = "stillcap_green"
+	icon_dead = "stillcap_green_dead"
+
+/datum/ai_controller/basic_controller/stillcap
+	blackboard = list(
+		BB_TARGETING_STRATEGY = /datum/targeting_strategy/basic/allow_items,
+		BB_PET_TARGETING_STRATEGY = /datum/targeting_strategy/basic/not_friends,
+		BB_BASIC_MOB_FLEE_DISTANCE = 25,
+		BB_AGGRO_RANGE = 5,
+		BB_TARGET_MINIMUM_STAT = HARD_CRIT,
+		BB_HIDING_HIDDEN = FALSE,
+		BB_HIDING_AGGRO_RANGE = DEFAULT_HIDING_AGGRO_RANGE,
+		BB_HIDING_COOLDOWN_MAXIMUM = 3 MINUTES,
+		BB_HIDING_COOLDOWN_MINIMUM = 1 MINUTES,
+		BB_HIDING_RANDOM_STOP_HIDING_CHANCE = 2,
+	)
+
+	ai_movement = /datum/ai_movement/basic_avoidance
+	idle_behavior = /datum/idle_behavior/idle_random_walk/hide
+
+	planning_subtrees = list(
+		/datum/ai_planning_subtree/pet_planning,
+		/datum/ai_planning_subtree/stop_hiding_if_target,
+		/datum/ai_planning_subtree/simple_find_nearest_target_to_flee,
+		/datum/ai_planning_subtree/stop_hiding_if_target,
+		/datum/ai_planning_subtree/flee_target,
+		/datum/ai_planning_subtree/random_hiding,
+		/datum/ai_planning_subtree/target_retaliate/check_faction/stop_hiding,
+		/datum/ai_planning_subtree/simple_find_target,
+		/datum/ai_planning_subtree/stop_hiding_if_target,
+		/datum/ai_planning_subtree/attack_obstacle_in_path,
+		/datum/ai_planning_subtree/basic_melee_attack_subtree,
+	)
diff --git a/monkestation/code/modules/map_gen_expansions/new_turfs.dm b/monkestation/code/modules/map_gen_expansions/new_turfs.dm
new file mode 100644
index 000000000000..0047f0e2b3a3
--- /dev/null
+++ b/monkestation/code/modules/map_gen_expansions/new_turfs.dm
@@ -0,0 +1,139 @@
+/turf/open/misc/asteroid/forest
+	gender = PLURAL
+	name = "grass"
+	desc = "A patch of grass."
+	icon = 'icons/turf/floors.dmi'
+	icon_state = "grass"
+	base_icon_state = "grass"
+	baseturfs = /turf/open/misc/dirt/forest
+	bullet_bounce_sound = null
+	footstep = FOOTSTEP_GRASS
+	barefootstep = FOOTSTEP_GRASS
+	clawfootstep = FOOTSTEP_GRASS
+	heavyfootstep = FOOTSTEP_GENERIC_HEAVY
+	smoothing_flags = SMOOTH_BITMASK | SMOOTH_BORDER
+	smoothing_groups = SMOOTH_GROUP_TURF_OPEN + SMOOTH_GROUP_FLOOR_GRASS
+	canSmoothWith = SMOOTH_GROUP_FLOOR_GRASS + SMOOTH_GROUP_CLOSED_TURFS
+	layer = HIGH_TURF_LAYER
+	//damaged_dmi = 'icons/turf/damaged.dmi'
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+	flags_1 = NONE
+	planetary_atmos = TRUE
+	dig_result = /obj/item/food/grown/grass
+	/// Which icon file to use for turf specific edge smoothing states.
+	var/smooth_icon = 'icons/turf/floors/grass.dmi'
+
+/turf/open/misc/asteroid/forest/Initialize(mapload)
+	. = ..()
+	if(smoothing_flags)
+		var/matrix/translation = new
+		translation.Translate(-9, -9)
+		transform = translation
+		icon = smooth_icon
+
+	if(is_station_level(z))
+		GLOB.station_turfs += src
+
+/turf/open/misc/asteroid/forest/getDug()
+	. = ..()
+	AddComponent(/datum/component/simple_farm)
+
+/turf/open/misc/asteroid/forest/mushroom
+	name = "mushroom floor"
+	desc = "A patch of mushrooms."
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/floors.dmi'
+	icon_state = "mushroom"
+	base_icon_state = "mushroom"
+	smoothing_groups = SMOOTH_GROUP_TURF_OPEN + SMOOTH_GROUP_MUSHROOM
+	canSmoothWith = SMOOTH_GROUP_CLOSED_TURFS + SMOOTH_GROUP_MUSHROOM
+	//damaged_dmi = 'icons/turf/damaged.dmi'
+	smooth_icon = 'monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom.dmi'
+	dig_result = /obj/item/food/grown/ash_flora
+	light_outer_range = 2
+	light_power = 0.50
+	light_color = COLOR_VERY_LIGHT_GRAY
+
+/turf/open/misc/asteroid/forest/mushroom/blue
+	icon_state = "mushroom_blue"
+	base_icon_state = "mushroom_blue"
+	smooth_icon = 'monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_blue.dmi'
+
+/turf/open/misc/asteroid/forest/mushroom/green
+	icon_state = "mushroom_green"
+	base_icon_state = "mushroom_green"
+	smooth_icon = 'monkestation/code/modules/map_gen_expansions/icons/turfs/floors/mushroom_green.dmi'
+
+/turf/open/openspace/forest
+	name = "open forest air"
+	baseturfs = /turf/open/openspace/forest
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+	planetary_atmos = TRUE
+
+/turf/open/misc/dirt/forest
+	desc = "Hard-packed dirt - much too hard to plant seeds in."
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+	planetary_atmos = TRUE
+
+/turf/open/misc/sandy_dirt/forest
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+	planetary_atmos = TRUE
+
+/turf/closed/mineral/random/forest
+	name = "forest mountainside"
+	icon = MAP_SWITCH('icons/turf/walls/mountain_wall.dmi', 'icons/turf/mining.dmi')
+	icon_state = "mountainrock"
+	base_icon_state = "mountain_wall"
+	smoothing_flags = SMOOTH_BITMASK | SMOOTH_BORDER
+	canSmoothWith = SMOOTH_GROUP_CLOSED_TURFS
+	defer_change = TRUE
+	turf_type = /turf/open/misc/dirt/forest
+	baseturfs = /turf/open/misc/dirt/forest
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+	weak_turf = TRUE
+
+/turf/closed/mineral/random/forest/Change_Ore(ore_type, random = 0)
+	. = ..()
+	if(mineralType)
+		icon = 'icons/turf/walls/icerock_wall.dmi'
+		icon_state = "icerock_wall-0"
+		base_icon_state = "icerock_wall"
+		smoothing_flags = SMOOTH_BITMASK | SMOOTH_BORDER
+
+/turf/closed/mineral/random/forest/mineral_chances()
+	return list(
+		/obj/item/stack/ore/bluespace_crystal = 1,
+		/obj/item/stack/ore/diamond = 1,
+		/obj/item/stack/ore/gold = 10,
+		/obj/item/stack/ore/iron = 40,
+		/obj/item/stack/ore/plasma = 20,
+		/obj/item/stack/ore/silver = 12,
+		/obj/item/stack/ore/titanium = 11,
+		/obj/item/stack/ore/uranium = 5,
+	)
+
+/turf/open/floor/engine/hull/reinforced/planetary
+	desc = "Sturdy exterior hull plating that separates you from the outside world"
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+
+/turf/open/floor/engine/hull/planetary
+	desc = "Sturdy exterior hull plating that separates you from the outside world."
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+
+/turf/open/lava/plasma/forest
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
+	baseturfs = /turf/open/lava/plasma/forest
+	planetary_atmos = TRUE
+
+	icon = 'monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest.dmi'
+	mask_icon = 'monkestation/code/modules/map_gen_expansions/icons/turfs/floors/plasma_forest_mask.dmi'
+	icon_state = "plasma_forest-255"
+	mask_state = "plasma_forest-255"
+	base_icon_state = "plasma_forest"
+	smoothing_flags = SMOOTH_BITMASK | SMOOTH_BORDER
+	smoothing_groups = SMOOTH_GROUP_TURF_OPEN + SMOOTH_GROUP_FLOOR_LAVA
+	canSmoothWith = SMOOTH_GROUP_FLOOR_LAVA
+	underfloor_accessibility = 2 //This avoids strangeness when routing pipes / wires along catwalks over lava
+
+/turf/open/floor/plating/forest
+	icon_state = "plating"
+	initial_gas_mix = FOREST_DEFAULT_ATMOS
diff --git a/tgstation.dme b/tgstation.dme
index 75560fda7457..fb319029ed2d 100644
--- a/tgstation.dme
+++ b/tgstation.dme
@@ -390,7 +390,9 @@
 #include "code\__DEFINES\~monkestation\antagonists.dm"
 #include "code\__DEFINES\~monkestation\artifact.dm"
 #include "code\__DEFINES\~monkestation\asteroids.dm"
+#include "code\__DEFINES\~monkestation\atmospherics.dm"
 #include "code\__DEFINES\~monkestation\atom_hud.dm"
+#include "code\__DEFINES\~monkestation\blackboard.dm"
 #include "code\__DEFINES\~monkestation\blueshift.dm"
 #include "code\__DEFINES\~monkestation\botany.dm"
 #include "code\__DEFINES\~monkestation\chat.dm"
@@ -6811,6 +6813,23 @@
 #include "monkestation\code\modules\logging\log_category.dm"
 #include "monkestation\code\modules\logging\log_holder.dm"
 #include "monkestation\code\modules\logging\categories\log_category_game.dm"
+#include "monkestation\code\modules\map_gen_expansions\_basemapping.dm"
+#include "monkestation\code\modules\map_gen_expansions\areas.dm"
+#include "monkestation\code\modules\map_gen_expansions\new_turfs.dm"
+#include "monkestation\code\modules\map_gen_expansions\ai\idle_behaviours.dm"
+#include "monkestation\code\modules\map_gen_expansions\ai\behaviours\hiding.dm"
+#include "monkestation\code\modules\map_gen_expansions\ai\subtree\find_target_not_hiding.dm"
+#include "monkestation\code\modules\map_gen_expansions\ai\subtree\hiding.dm"
+#include "monkestation\code\modules\map_gen_expansions\ai\subtree\retaliate_target.dm"
+#include "monkestation\code\modules\map_gen_expansions\ai\subtree\stop_hiding_if_target.dm"
+#include "monkestation\code\modules\map_gen_expansions\elements\can_hide.dm"
+#include "monkestation\code\modules\map_gen_expansions\forest\atmosphere.dm"
+#include "monkestation\code\modules\map_gen_expansions\forest\generator.dm"
+#include "monkestation\code\modules\map_gen_expansions\forest\mobs\deer.dm"
+#include "monkestation\code\modules\map_gen_expansions\forest\mobs\megadeer.dm"
+#include "monkestation\code\modules\map_gen_expansions\mushroom\flora.dm"
+#include "monkestation\code\modules\map_gen_expansions\mushroom\generator.dm"
+#include "monkestation\code\modules\map_gen_expansions\mushroom\mobs\stillcaps.dm"
 #include "monkestation\code\modules\mapping\access_helpers.dm"
 #include "monkestation\code\modules\mapping\mapping_helpers.dm"
 #include "monkestation\code\modules\maptext\maptext_image_helper.dm"