The 3 guys on the left are half-arsed-from-memory renditions of characters from a CSUF grad student named... Woody. He had a very impressive MFA in Illustration exhibit, where he had many well-made (cartoony, humorous, inked+watercolored!) comic pages displayed.
The pencil drawings in the middle-right are done by Christina. Yep. Pretty good.
Upper right: I can actually draw a better pic of Christina; this was just my first attempt. I should try doing stuff like this more...!