Cast
- Steve Buscemi as Scamper (voice)
- Christian Slater as Dr. Schadenfreude's Igor (voice)
- Jennifer Coolidge as Jaclyn / Heidi (voice)
- Molly Shannon as Eva (voice)
- John Cusack as Igor (voice)
- Eddie Izzard as Dr. Schadenfreude (voice)
- Sean Hayes as Brain (voice)
- Jess Harnell as Announcer / Royal Guard #2 (voice)
- John Cleese as Dr. Glickenstein (voice)
- Jay Leno as King Malbert (voice)
- Arsenio Hall as Carl Cristall (voice)
- James Lipton as Himself
- Myleene Klass as Dr. Holzwurm (voice)
- Robin Walsh as Dr. Holzwurm's Igor (voice)
- Matt McKenna as Dr. Herzschlag (voice)