About a month before Team Fortress 2 dropped, a friend of mine commissioned fan-art of his character as the Sniper character based on the pre-release videos that Valve had put out. Naturally, I had to get one for myself, as a class more fitting for my dragon character. The artist uploaded another TF2 drawing the same day as mine, and filled out the rest of the roster in the weeks that followed -- I don't think he ever posted a journal saying he was doing a set of them, it just sort of happened.
Art by ayato, 2007