The etymology of Fisty McTatt

[Pitt Gorilla]

I began noticing Fisty popping up in various threads and avatars, seemingly, not that long ago. Realizing that I had missed something somewhat monumental, I began trying to piece together his history. However, it appears that I'm still missing quite a bit.

I read the Chiefs tattoo thread, but he had already risen to prominence by that time. I've seen various iterations that include other bits of pop culture (the basketball fan-kid). However, I still can't figure out where it all started. Any information/citation would be greatly appreciated.