Two Heads are Better?

When given an assignment to illustrate a story about a two headed man, where both heads have completely different personalities and looks, I knew exactly who I wanted to use. Brennan and Griffin are a couple friends, really fun guys and step-brothers. I bribed them over with fried chicken, took photos of them and worked out this composition.

The background is still in flux. Initially I was thinking fire/smoke on one side turning into butterflies ( a significant image in the story) but the paint is telling me this may not work. Also Grif (the one on the right) will be a bit more sinister in the final.