Custom characters in Overgrowth.
Creating new characters in Overgrowth is not an easy process. However there are a few methods that vary in difficulty.
The easiest method would be to use an existing character and attach different static objects to the bones. This can drastically change the appearance but require no external software. The downside however, is that the objects do not conform to the character's mesh. Meaning things like clothing will not move with, bend or fold with the character in a realistic way.
To attach an object to a character go into Editor Mode by pressing F1. Select the object you want to attach and move it in the correct position. To make it easier to attach it press ~ to freeze time, allowing you to position it correctly without the character moving. Now press and hold the Alt button. A few lines should appear to represent the different bones you can attach to. With the Alt button down, you can attach the object by clicking with the left mouse button. To detach hold Shift as well and click the same bone.