Harvey Birdman, Attorney at Law

Thomas Allen

Peanut (voice)

John Michael Higgins

Mentok the Mindtaker (voice)

Chris Edgerly

Peter Potamus (voice)

Gary Cole

Harvey Birdman (voice), Judge Hiram Mightor (voice)

Peter MacNicol

X the Eliminator (voice)

Paget Brewster

Birdgirl (voice)

Stephen Colbert

FBI (voice; uncredited), Civilian #1 / Juror (voice), Phil Ken Sebben / Myron Reducto (voice), Fed #2 (voice), Pirate (voice)

Bill Farmer

Secret Squirrel (voice)

Paul Adelstein

Michael McKean

Evelyn Spyro Throckmorton (voice)

Nika Futterman

Patience Cleveland

Mark Hamill

Ricochet Rabbit (voice)

Neil Ross

Dr. Benton C. Quest / Vulturo (voice)

Mary Birdsong

Debi Mae West

Rob Paulsen

Toby Huss

Kym Whitley

Robert Osborne

Diane Michelle

Lewis Black

The Deadly Duplicator (voice)

Wally Wingert

Hadji (voice)

Billy West

Dr. Zin (voice)

Scott Innes

Shaggy Rogers / Scooby-Doo / Scrappy-Doo / Prisoner #1 (voice)

Phil LaMarr

FEAR #2 / Black Vulcan (voice), Black Vulcan / Civilian #2 (voice)

Jack Angel

General / Drunk Man / Additional Voices (voice)

Michael Bell

Zan (voice)

Laraine Newman

Sybil Scussler / Mrs. Debbie (voice)

Steve Landesberg

Grok (voice), Bailiff (voice), Doctor Quincy (voice)

Jeff Bergman

George Jetson / Bakov / Clown (voice)

B.J. Ward

Velma Dinkley (voice)

Maurice LaMarche

Yogi Bear (voice), Azul Falcone (voice), Azul Falcone / Stan Freezoid (voice), Fred Flintstone / Bird / Can Opener (voice), Apache Chief / Announcer (voice)

Tom Kenny

Elroy (voice), Boo Boo (voice), Top Cat (voice)

Dee Bradley Baker

Forensic Pathologist / Foreman / Lizardman (voice), Jonny Quest / Lizardman / Avenger (voice)

Frank Welker

Jabberjaw / Biff (voice), Avenger / Fed #1 / Juror (voice), Jabberjaw (voice), Fred Jones / Avenger / Robot (voice)

Jeanne Mori

Seiko / Miko (voice)

Toshi Toda

Shoyu Weenie's Manager (voice)

Tress MacNeille

Wilma Flintstone / Pebbles Flintstone (voice)

Doug Preis

Thundarr (voice)

Kevin Michael Richardson

Barney Rubble (voice)

Grey DeLisle

Debbie (voice), Receptionist (voice), Debbie / DMV Operator / X's Wife (voice), Daphne Blake / Mrs. Debbie (voice), Dr. Gale Melody / Debbie (voice)

Carol Bach Rita

Talia (voice), Operator (voice)

Joe Alaskey

Peter Potamus / Employee (voice), FEAR #1 / Peter Potamus (voice)

David Kaye

Announcer / Officer (voice), Officer (voice)

André Sogliuzzo

Dynomutt / Avenger / Co-Worker (voice), Dynomutt / Avenger / Pope (voice)