Devon Werkheiser

as Casper / Casper's Shadow (voice)

Brett DelBuono

as Jimmy (voice)

Jim Belushi

as Alder (voice)

Bob Saget

as Dash (voice)

John DiMaggio

as Stinkie / Frankengymteacher (voice)

Billy West

as Fatso / Figurehead (voice)

Dan Castellaneta

as Stretch (voice)

Kevin Michael Richardson

as Kibosh (voice)

Matthew Underwood

as Thatch (voice)

Christy Carlson Romano

as Mantha (voice)

Candi Milo

as Mickey (voice)

Nika Futterman

as Monaco (voice)

Kendre Berry

as Ra (voice)

Debi Derryberry

as Banana Lady / History Teacher / Additional Voices (voice)

Pat Fraley

as Scare Center Host 1 / Wolfie / Narrator / Werewolf / Additional Voices (voice)

Scott Menville

as Punk Kid / Scare Center Host 2 / Pumpkinhead / Brainiac / Pool Guy / Hunchback / Additional Voices (voice)

Maurice LaMarche

as Pirate / Thurdigree Burns (voice)

Kevin McDonald

as Parrot (voice)

Terri Douglas

as Fish Boy / Drip / Additional Voices (voice)

John Kassir

as P.A. Voice / Additional Voices (voice)

Phyllis Diller

as Aunt Spitzy (voice)

Jason Harris

as Gargoyle / Flyboy / Skinny Ghost / Coach / Additional Voices (voice)

Daryl Dragon

as Murray (voice)

Toni Tennille

as Belle (voice)

Danny Cooksey

as Additional Voices (voice)

Fred Tatasciore

as Additional Voices (voice)