A DooM Demon. Better known as 'Squiddie' or something like that, DooM freaks among you will probably recognize it.
I made this as a base for the texture that can be found among my DooM textures, but I figured this was worthy of adding to my painting section (without overlays and texture details).
This was a lot of fun for me to do, and it took me about 2-3 days.