Many writers for The Simpsons are Harvard alums. The Harvard Lampoon (a campus humor magazine which sucks) sends many of its alums to write for shows such as Letterman, SNL, Conan O'Brian (who is an alumni himself), and The Simpsons. This group of writers takes many opportunities to mock their favorite rivals, Princeton and Yale, and occasionally themselves. Some examples:

-In the episode where Bart and Lisa write Itchy and Scratchy cartoons, one of the I&S writers is a Harvard alum who is abused and fired by the show's producer. Great moment: the producer calls the alum to make him sing "Fair Harvard", then throws a paperweight at his head, prompting him to say, "You, sir, have the boorish manners of a Yalie"

-At the end of one of the Sideshow Bob episodes, Bob is returned to his minimum-security prison, where a boatful of rowers calls out to him to help row against "the alums from Princeton", causing him to say "[shudder], Princeton", and hop in.

-During the Sideshow Bob and Cecil episode, Bob and Cecil have and argument, during which Bob points out Cecil's "four years in clown college", to which he replies, "I would prefer it if you not refer to Princeton in that manner"

There may be others, but I forget or have not caught them.