En afdanket tryllekunstner, den fabelagtige Krudsky, stjæler den magsiek lyskraft fra feprinsesse Willow. Nu er det op til Scooby-Doo og hans venner at stoppe ham, før han forvandler alle til Halloween-monstre.

The gang from Mystery, Inc., is once again on the case in this royally fun, spooky adventure! This time, Scooby-Doo, the almost-never brave Great Dane detective, matches wits with the king of the Goblins. Can Scooby, along with his friends Shaggy, Fred, Velma and Daphne, get to the bottom of the mystery and stop the Goblin King from succeeding at his wicked plans, or will the monster prevail? With "those meddling kids" and Scooby-Doo on his case, he doesn't have a ghost of a chance.

haggy, Scooby og gjengen besøker et uhyggelig karneval for skremmende moro på Halloween, men alt er ikke som det ser ut da den onde Demonkongen dukker opp!