Scooby-Doo and Shaggy must go into the underworld ruled by The Goblin King in order to stop a mortal named The Amazing Krudsky who wants power and is a threat to their pals: Fred, Velma, and Daphne.
| Actor | Role |
|---|---|
 Frank WelkerScooby-Doo / Fred Jones (voice) | Scooby-Doo / Fred Jones (voice) |
 Casey KasemShaggy Rogers (voice) | Shaggy Rogers (voice) |
 Grey DeLisleDaphne Blake / Cat Witch / Honeybee (voice) | Daphne Blake / Cat Witch / Honeybee (voice) |
 Mindy CohnVelma Dinkley (voice) | Velma Dinkley (voice) |
 Lauren BacallThe Grand Witch (voice) | The Grand Witch (voice) |
 Tim CurryThe Goblin King (voice) | The Goblin King (voice) |
 Jim BelushiGlob (voice) | Glob (voice) |
 Wayne KnightThe Amazing Krudsky (voice) | The Amazing Krudsky (voice) |
 Wallace ShawnMr. Gibbles (voice) | Mr. Gibbles (voice) |
 Hayden PanettiereFairy Princess Willow (voice) | Fairy Princess Willow (voice) |
 Larry Joe CampbellGlum (voice) | Glum (voice) |
 Jay LenoJack O'Lantern (voice) | Jack O'Lantern (voice) |
 Thom Adcox-HernandezSparkplug (voice) | Sparkplug (voice) |
 Russi TaylorOwl Witch / Tiddlywink (voice) | Owl Witch / Tiddlywink (voice) |