John Cusack

Igor (voice)

Myleene Klass

Dr. Holzwurm (voice)

Robin Walsh

Dr. Holzwurm's Igor (voice)

Matt McKenna

Dr. Herzschlag (voice)

John Cleese

Dr. Glickenstein (voice)

Steve Buscemi

Scamper (voice)

Sean Hayes

Brain (voice)

Eddie Izzard

Dr. Schadenfreude (voice)

Jay Leno

King Malbert (voice)

Jennifer Coolidge

Jaclyn / Heidi (voice)

Molly Shannon

Eva (voice)

James Lipton

Himself

Christian Slater

Dr. Schadenfreude's Igor (voice)

Arsenio Hall

Carl Cristall (voice)

Jess Harnell

Announcer / Royal Guard #2 (voice)

Zoë Bright

Blind Woman / Killiseum Fan #1 (voice)

Sophia Eraklis

Blind Orphan #1 (voice)

A. Cheron Hall

Blind Orphan #2 / Blind Orphan #4 (voice)

Alexander Leondis

Blind Orphan #3 (voice)

Michael Leondis

Blind Orphan #6 (voice)

Nicole Leondis

Blind Orphan #7 (voice)

Juliana Leondis

Blind Orphan #5 (voice)

Robin Tisserand

Blind Orphan #8 (voice)

Paul Vogt

Buzz Offmann (voice)

Frank Welker

Animals' vocal effects (voice) (uncredited)