Count Dracula transforms Shaggy into a fuzz-faced werewolf and there's only one way he will change him back. Scooby-Doo and Shaggy must win a creepy cross-country race against a hot-rodding horde of sinister celebrity monsters.

Count Dracula has until midnight to retrieve an ancient amulet that will give him final control over the delicate balance between good and evil in the world. To help him, the creepy Count calls on some old friends; the weird Wolfman, grotesque Gill-Man, mildewed Mummy and freaky Frankenstein. As the ghoulish group gets closer to the amulet, it becomes up to the Monster Squad, headquartered in the local tree house, to pool its questionable resources...