Game Character Hub - helper program for game design (RPG Maker XP/VX and more)
Blender - Blender is the open source, cross platform suite of tools for 3D creation.
pixeldudesmaker - Simple, web-based pixel art character generator.
Unreal Engine - Unreal Engine 4 is a suite of integrated tools for game developers to design and build games, simulations, and visualizations.
RPG Character Builder - Create thousands of unique character sprites for your 2D game project - free!
Unity - The multiplatform game creation tools for everyone.