I was going to do something with a caveman for this topic, but I saw a few of those appearing on the link viewer...
I've been looking for an excuse to do a illustration of the HULK. So, to relate it to the topic... I think his anger comes from the primitive/primeval part of his brain, the animal instincts.
I'm sure it'll come as no surprise to those of you who know me and those of you who've been following my blog for a while that I loved the 70's series of the HULK starring Bill Bixby and Lou Ferrigno.
"Don't make me angry, you wouldn't like me when I'm angry..."
I wanted my Hulk to be as ridiculously proportioned as I felt possible - that's where the fun of the character is for me!