[necrocomment]
Zizka seems to have used this Might and Magic Heroes VI unit as the reference:
static9.cdn.ubi.com/en-US/images/MMH6_CA_INFERNO_05_Breedertcm1912246.jpg
static9.cdn.ubi.com/en-US/images/MMH6_CA_INFERNO_05_Mother_Breedertcm1912247.jpg
May be you`ve been wondering about that every night since the moment you saw it. :P
it feels it comes from an rpg videogame. I think. it looks like.
I would like to see it animated. nice work on it. 
I didn't actually know it was from Might & Magic VI. I found the reference from google image by typing "hell spawn" as mentioned in the original thread over at pixelation: http://wayofthepixel.net/index.php?topic=16261.0 (which you had probably also seen there along with the original reference...).