No idea. One of those free avatar sites. I usually favorite any site that I get stuff from, but lately, I haven't.
It's the icon for Shadow Word: Pain for a Priest in WoW. Not sure what ability it is for WC3 though...
I make my avatars myself (mostly by resizing stuff ), but I don't very like wasting time on it, so I do it rarely. I'll probably stick to my current one for now.
Meh the funnier the better so I would say that I change my avatar occasionally when I find something good