i'm no expert on this but i would think that you can carve him out of a 3D teddy bear cake pan...it was the first thought that popped into my head....wish i could be of more help
Does it have to be the whole body? If not, I was thinking of just doing the bust. Have you seen some of the great spiderman ones that have been posted here at CC? I've seen people revamp them into Superman and various other characters. I bet a Hulk would work too!!!
if you just want the face, there is the Wilton bear face pan that might give you a good starting shape? Good luck with that one!
I'm doing a Hulk bust cake today.......doing just like I did the superman, batman, and cookie monster cake. I will post a picture of the Hulk when I get it done today! I am going to use rice krispies to make his face more blocky though, my mannequin head is a female so it needs some help. You can also check out my pictures, I have some step by step pitures of one of the bust cakes I did. (I think it is the batman one). I don't know if this post is to late to help you, but if not I hope it will help someone.