Scooby-Doo and the Ghoul School

Scooby-Doo, Shaggy, and Scrappy arrive to work as gym teachers at Miss Grimwood's Finishing School for Girls. They are initially wary upon discovering the school houses daughters of paranormal beings, but the girls quickly take a liking to them and convince them to stay.

The school is filled with extraordinary residents and pupils, including Sibella Dracula's daughter, Elsa Frankenteen, Winnie the Wolfman's daughter, Phantasma, and Tanis, daughter of the Mummy. There are quirky companions like a disembodied white hand, an octopus butler, a two-headed shark in the moat, and a helpful spider named Legs.

During the annual volleyball match against Calloway Military Academy, the boys secretly rig the ball with a remote control. Scooby accidentally swallows the remote, allowing the girls to win the game. The moment confirms the school's unusual but endearing spirit.

The girls' fathers visit for an open house party on Halloween night. The party is lively and surprisingly cordial, but they warn Shaggy and Scooby not to let any harm come to their daughters. The warning reinforces the seriousness of protecting the girls.

Power-hungry witch Revolta and her minion Grim Creeper plot to kidnap the girls and enslave them. Revolta hypnotizes Shaggy into taking the girls on a field trip to the Barren Bog.

The field trip to the Barren Bog begins, with Matches told to stay behind. The Calloway Cadets get stuck in quicksand, but Elsa and Tanis rescue them, proving the girls' resourcefulness.

Revolta's spider-bats begin capturing the girls one by one at the bog. Revolta completes a potion that is meant to turn them evil forever at the stroke of midnight.

Scooby, Scrappy, Shaggy, and Matches reach Revolta's castle to rescue the girls and confront the evil scheme. They face a Mirror Monster that can imitate anyone who looks into its mirror, a giant Well Dweller, and Revolta herself.

At midnight, Revolta administers the potion to the girls through hairdryers, intending to turn them evil. Scooby and Shaggy interrupt and reverse the potion's effect.

Elsa throws Revolta's wand into the potion, triggering a violent explosion that destroys the potion and thwarts Revolta's plan. The castle's chaos ends and the heroes rally the students and Cadets to safety.

The Calloway Cadets arrive in a pedal-powered helicopter and rescue everyone from the danger outside. They fly the heroes and the pupils to safety, while Revolta swears vengeance.

The Cadets and Grimwood Girls throw a party to celebrate Revolta's defeat and everyone's bravery. The school is safe, and Shaggy and Scooby are celebrated despite being anxious about future monsters.

Shaggy, Scooby, and Scrappy flee the school in terror at the thought of new monsters enrolling their daughters next year. They wave goodbye to the girls and the rescued companions, sharing one last werewolf howl as they drive off into the night.