This won't be news to anyone who follows Phil Foglio's career, but Foglio, like Hitchcock, inserts himself (to be exact, a very specific caricature of himself) into pretty much every series he draws.
Remember yesterday when I mentioned his first strip, What's New with Phil and Dixie? Well, the Phil of the title was Foglio himself, explicitly referred to by last name on more than one occasion (as in the sample panel here). This strip ran in Dragon magazine in 1981.
Notice the very specific outfit he's wearing here: white turtleneck sweater and bowler hat. Now look at the following panels from:
D'Arc Tangent, 1982...
Buck Godot, Zap Gun For Hire, 1986 (sorry about the crappy scan, but I didn't want to destroy my trade paperback to scan part of one page) (ETA: Buck Godot's continuing adventures can be read online here)...
and Girl Genius, 2006.
I haven't dug my XXXenophile issues out of the Vault yet, so I have no idea if Phil appears in those or not. It probably doesn't matter to anyone but me, anyway, but I find it amusing.