A Man Crab attacks Crystal Cove beach during a volleyball tournament for Trickell's Triquid diet mixture. The gang must stop him and solve this mystery before the tournament's female players, who the Man Crab has taken a liking to, are put in danger.
A hideous creature named QUE HORRIFICO is turning the children of Crystal Cove in to monsters. The adults in the town are in shock, reacting in the only way they know how... By abandoning their children and running away like cowards.
When Fred asks new student Alice May to the prom, Daphne becomes convinced that the girl is a phantom who wants to add Fred to her "man posse." Meanwhile, Shaggy skips out on watching a horror marathon with Scooby to go to prom with Velma.
A pair of brutal GARGANTUAS begin breaking apart the town, which sadly mirrors the fractured relationship of MYSTERY INC. See, while searching for Shaggy, Scooby accidentally discovers him KANOODLING WITH VELMA.
After a horrible, mechanized BEAST begins attacking the town, all fingers begin pointing at Scooby. Before the gang can clear his name, the Sheriff has Scooby hauled away to the CRYSTAL COVE ASYLUM FOR CRIMINALLY INSANE ANIMALS.