Fred/Scooby
Frank Welker
Shaggy Rogers (voice)
Matthew Lillard
Velma Dinkley (voice)
Mindy Cohn
Daphne
Grey DeLisle
Rick Yantz/Announcer/Hospital PA
Dave "Gruber" Allen
Kriegstaffebot (Voice) / Gene Shepherd (voice) / Junk (voice)
Dee Bradley Baker
Ernesto/Todd
Carlos Alazraqui
Dr. Henklefust
John Billingsley
Nova
Amy Acker
Luna
Kimberly Brooks
Eager Clerk/Clerk's Pet
Eric Bauza
Dreamweaver (voice) / Curator Vronsky (voice) / Krod (voice)
Troy Baker
Mary-Ann Geerdon/Tiffany
Isabella Acres
Captain Caveman
Jim Cummings
Professor Horatio Kharon
Michael J. Anderson
Older Danny Darrow
Dwight Schultz
Mr. E (voice) / Mr. E (voice) / Mr. E
Lewis Black
Sheila Altoonian
Beverly D'Angelo
Dead Justice
Powers Boothe
Bud Coleman
David Faustino
Gary (voice) / Gary / Referee #2 (voice)
Tony Cervone
Arthur Baywosenthal
Zach Callison
Angel Dynamite (voice) / Cassidy Williams (voice) / Cassidy Williams
Vivica A. Fox
Marcie 'Hot Dog Water' Fleach (voice) / Marcy 'Hot Dog Water' Fleach (voice) / Hot Dog Water (voice)
Linda Cardellini
Sheriff Bronson Stone (voice) / Sheriff Stone (voice)
Patrick Warburton
Professor Enrique Andelusossa
Christian Lenz
H.P. Hatecraft
Jeffrey Combs
Charles "Cachinga" Wheatlesby/Destroido Computer
Greg Ellis
Hugh Dederdee
Joe Holt
Daniel Prezette/Frantzee Pantz/Gus Boggs
Quinton Flynn
Dan Fluunk/Fiend
Kevin Michael Richardson
Younger Danny Darrow
Will Shadley
Mayor Janet Nettles (voice) / Principal Quinlan (voice)
Kate Higgins
Garden Manager/Maitre D'
Kevin Dunn
Evallo Von Meanskrieg
Chris Hardwick
Mayor Fred Jones Sr. (voice) / Mayor Fred Jones Sr. / Motorcycle Cop (voice)
Gary Cole
Granny Snaggletooth
Laraine Newman
Angie Dinkley (voice) / Mrs. Dinkley (voice)
Frances Conroy
Lady Marmalade
Cree Summer
Weena/Waitress
April Winchell
Thorn
Jennifer Hale
Ed Machine/Announcer/Creepy Voice
Richard McGonagle
Ruby Stone
Florence Henderson
Professor Pericles (voice)
Udo Kier
Chen/Red Wizard
James Hong
Marion Spartan
Julie Bowen
Young Man/Ben
David Markus
Nibiru
Clancy Brown
Picnicker
Clyde Kusatsu
Funky Phantom/Chairman
Tom Kenny
Fernando El Aguirre
Christian Lanz
Harry Schnesle-Boysen
David Juskow
Grandma Moonbeam
Marion Ross
Gunther Gator
Billy West
Vincent Van Ghoul (voice)
Maurice LaMarche
Race Bannon/Bobo
Christopher Corey Smith
Jason
Daryl Sabara
Skipper's Brother
Daran Norris
Aphrodite/Amanda Smyth
Tricia Helfer
Skipper Shelton (voice)
John O'Hurley
Mai Le
Stephanie Sheh
Melvin Keisterbaum
Phil LaMarr
Himself
Harlan Ellison
Crybaby Clown
Mark Hamill
Dandy Highwayman
James Marsters
Winslow Fleach
Rob Paulsen
Colton Rogers
Casey Kasem
Dr. Rick Spartan
James Patrick Stuart
Frau Gluck
Mindy Sterling
Mr. Wang/White Wizard
George Takei
Demon Dog
Fred Tatasciore
Peter Trickell
George Segal
Grady Gator/Delivery Guy
John DiMaggio
George Avocados (voice) / George Avocados / Rung Ladderton
James Arnold Taylor
Gill Littlefoot
Jeffrey Tambor
Kelsepsian/Jingle Singer/Hairy Sasquach
Paul Rugg
Gabtraf
Phil Idrissi
Brad Chiles (voice)
Tim Matheson
Judy Reeves (voice) / Amy (voice)
Tia Carrere
Herself
Martha Quinn
Nan Blake (voice)
Kath Soucie
Professor Emmanuel Raffalo/Tourist
Jeff Bennett
Dr. Cavanaugh
Gary Anthony Williams
Odnarb
Ben McKenzie
Lord Infernicus/Boo
Rick Wasserman
Jason's Mom
Jessica Walter
Baylor Hotner
Matt Lanter
Ben/Rhino/Cook/Howard E. Robertson
Crispin Freeman
Brenda
Beth Tapper
Lord Barry
Lloyd Sherr
Dad
David Kaye
Alice May
Hynden Walch
Ned Fussbuster
Charles Shaughnessy
Dusk
Jane Wiedlin
J.R. Kipple
Jim Rash
Horbert Feist
Jason Marsden
Gorgeous G
Roz Ryan
Queen Amanda
Audrey Wasilewski
Ethan (voice) / Farmer (voice)
Mitch Watson
Judy Reeves/Regina Wentworth
Kari Wahlgren
Ricky Owens
Scott Menville
Brad Chiles
Nolan North