The gang goes on a trip to check on Velma's younger sister, Madelyn. She's been studying stage magic at the Whirlen Merlin Magic Academy, where apparently there have been sightings of a giant griffin. The gang decides to investigate.
| Actor | Role |
|---|---|
 Frank WelkerScooby-Doo / Fred Jones (voice) | Scooby-Doo / Fred Jones (voice) |
 Matthew LillardShaggy Rogers (voice) | Shaggy Rogers (voice) |
 Mindy CohnVelma Dinkley (voice) | Velma Dinkley (voice) |
 Grey DeLisleDaphne Blake (voice) | Daphne Blake (voice) |
 Danica McKellarMadelyn Dinkley (voice) | Madelyn Dinkley (voice) |
 James Patrick StuartWhirlen Merlin (voice) | Whirlen Merlin (voice) |
 Crystal ScalesCrystal (voice) | Crystal (voice) |
 Brian PosehnMarlon Whirlen (voice) | Marlon Whirlen (voice) |
 Jeffrey TamborMr. Calvin Curdles (voice) | Mr. Calvin Curdles (voice) |
 Diane DelanoMrs. Alma Rumblebuns (voice) | Mrs. Alma Rumblebuns (voice) |
 John DiMaggioGroundskeeper Amos (voice) | Groundskeeper Amos (voice) |
 Melique BergerUpset Mother (voice) | Upset Mother (voice) |
 John StephensonThe Sheriff (voice) | The Sheriff (voice) |
 Dee Bradley BakerSherman (voice) | Sherman (voice) |
 Olivia HackTreena (voice) | Treena (voice) |
 Dave AttellGPS (voice) | GPS (voice) |