With Mystery, Inc. on the tail of a strange object in Nowhere, Kansas, the strange hometown of Eustace, Muriel, and Courage, the gang soon find themselves contending with a giant cicada monster and her winged warriors.
| Actor | Role |
|---|---|
 Matthew LillardShaggy Rogers (voice) | Shaggy Rogers (voice) |
 Thea WhiteMuriel Bagge / Rich Old Lady (voice) | Muriel Bagge / Rich Old Lady (voice) |
 Grey DeLisleDaphne Blake / Frau Glockenspiel (voice) | Daphne Blake / Frau Glockenspiel (voice) |
 Frank WelkerScooby-Doo / Fred Jones (voice) | Scooby-Doo / Fred Jones (voice) |
 Kate MicucciVelma Dinkley (voice) | Velma Dinkley (voice) |
 Jeff BennettThe General / Self Help Book (voice) | The General / Self Help Book (voice) |
 Paul SchoefflerKatz / Le Quack / Narrator (voice) | Katz / Le Quack / Narrator (voice) |
 Marty GrabsteinCourage / Mr. McGill (voice) | Courage / Mr. McGill (voice) |
 Jeff BergmanEustice Bagge / Computer / Mayor of Nowhere (voice) | Eustice Bagge / Computer / Mayor of Nowhere (voice) |
 Chuck MontgomeryThe Lieutenant / Mr. Glockenspiel (voice) | The Lieutenant / Mr. Glockenspiel (voice) |