Mario and Luigi, plumbers from Brooklyn, find themselves in an alternate universe where evolved dinosaurs live in hi-tech squalor. They're the only hope to save our universe from invasion by the dino dictator, Koopa.

Tom McHugh quickly learns that his perfect big brother Craig isn't all he's cracked up to be while on a night on the town with the girl next door, during which Tom is harassed by unpleasant strangers, threatened by mobsters, pursued by police, attacked by an irate florist, accused of murder, and has his date kidnapped—all because everyone thinks he's Craig...and the classic 1959 DeSoto Firesweep he borrowed off his brother has two dead bodies in the trunk.

Princess Yum Yum falls in love with Tack and saves him from being executed. Later, when the protective orbs of the palace get stolen, Tack and Yum Yum set out to find them and save the kingdom.