Someone's been stealing from Daphne's uncle's joke shop, and it's up to the kids from Mystery, Inc. to get to the bottom of it. They help Uncle Walt try to drum up business by throwing a birthday bash for the mayor's son, but trouble's in store when a creepy clown shows up to prank the party guests. Will Shaggy, Scooby, and the rest of the gang catch the Phantom Prankster before the joke's on them?
