Frank Welker
Scooby-Doo / Rudy / Fred / Nefario (voice)
Grey DeLisle
Daphne / Daisy / Musketeer 1 / Olive (voice)
Matthew Lillard
Shaggy / Craggly / Captain Cutler (voice)
Kate Micucci
Velma / Helga (voice)
Myrna Velasco
Coco Diablo (voice)
Dee Bradley Baker
Esteban / Mr. Wickles / Cat Man (voice)
Jeff Bennett
Shady Guy / Charlie Humdrum / Hank (voice)
Anthony Carrigan
Trevor Glume / Farmer (voice)
Erin Fitzgerald
Library Kid / Superhero Girl / Musketeer 2 (voice)
David Lodge
Warden Collins / Harry the Hypnotist / Inspector (voice)
Lara Jill Miller
Prisoner Costume Teen / Superhero Boy / Musketeer 3 (voice)
Candi Milo
Prison Woman / Dinosaur Kid / Monster Kid (voice)
Jenelle Lynn Randall
Librarian / Superboy (voice)
Kevin Michael Richardson
Sheriff / Henry Bascombe / 10,000 Volt Ghost (voice)