I apologise if this has already been covered, but I just checked the CWCki and there's no mention of it there.
I've always wondered where and how Chrissy got the idea into his head of punching himself in the face to make him look hard. It just this moment struck me (I'm bracing myself for the barrage of 'slowpoke' cries here!) that the idea comes from Family Guy, the episode 'Stew-Roids' to be exact. Here's the clip -
[youtube]R0qp3thGBZ8[/youtube]
The fact that he took this as genuine behavior to intimidate someone and look tough is hilarious. Oh Chrissy, you bellend.
if anything, the fact that it was parodied on Family Guy as typical 'roided out tough-guy' behavior means that Chris could have picked it up from any number of places. (including, but not limited to, that episode.)