Shark attack: Xander’s line in the library, as he sees the foldout illustration of the demon Olvikan, "We’re going to need a bigger boat" misquotes Steven Spielberg’s terrific 1975 movie Jaws. The line is one of the most famous quotes in cinema history. The line is delivered by police chief Brody (Roy Scheider), just after has caught his first glimpse of a great white shark that’s been terrorizing a small coastal town: "You’re going to need a bigger boat!"
Tiger tiger: Willow's vain hope that Siegfried and Roy might be the speakers at the graduation ceremony is a reference to a pair of flamboyant magicians who perform in a spectacular Las Vegas show. They are famous for their elaborate costumes and their menagerie of big cats, including white tigers.
Willow the warrior: If you were confused by Willow’s reaction in the scene where Percy thanks Willow for "not kicking my ass, like you did in the Bronze", you should remember that it was actually the alternate universe Evil Willow who was the perpetrator, a reference to Doppelgängland.