Casey Kasem

Shaggy Rogers / Mirror Monster (voice)

Don Messick

Scooby-Doo / Scrappy-Doo (voice)

Glynis Johns

Ms. Grimwood (voice)

Susan Blu

Sibella Dracula (voice)

Pat Musick

Elsa Frankensteen (voice)

Russi Taylor

Phantasma (voice)

Frank Welker

Matches / Papa Werewolf / Well Dweller (voice)

Andre Stojka

The Grim Creeper / Mummy Daddy (voice)

Hamilton Camp

Phantom Father (voice)

Ruta Lee

Revolta (voice)

Ronnie Schell

Colonel Calloway (voice)

Scott Menville

Cadet Tug Roper (voice)

Aaron Lohr

Cadet Miguel (voice)

Bumper Robinson

Cadet Jamaal (voice)

Remy Auberjonois

Cadet Baxter (voice)

Jeff Cohen

Cadet Grunt (voice)

Brian Cummings

Fan Monster (uncredited voice)