Hi Lucy. It was already guessed by Dachs, so if you're going for the cookie mentioned in the avatar discussion, it's already given.
But no. It's a back.
It's a cropped frame from Akira, a nasty science fiction anime from the late eigthies I think. The avatar is displaying Tetsuo Shima's back as he is being transformed into a huge baby-like fleshy creature and consumes all of his friends, including a girl in dear love with him who pops like a zit when clenched between his entrails (Yes he sorta grows with his skin covering his friends) and the blood flows out; it is a splendidly horrific scene that freaks me out every time I watch it. The movie itself is somewhat gory.
I don't know why I wrote all of this, perhaps too much information of what you wanted to hear. Oh well.