| Spencer Klein | ... Arnold (voice) |
| Francesca Marie Smith | ... Helga / Deep Voice (voice) |
| Jamil Smith | ... Gerald / Rasta Guy (voice) |
| Dan Castellaneta | ... Grandpa / Nick Vermicelli (voice) |
| Tress MacNeille | ... Grandma / Mayor Dixie / Red (voice) |
| Paul Sorvino | ... Scheck (voice) |
| Jennifer Jason Leigh | ... Bridget (voice) |
| Christopher Lloyd | ... Coroner (voice) |
| Vincent Schiavelli | ... Mr. Bailey (voice) |
| Maurice LaMarche | ... Big Bob / Head of Security (voice) |
| Kath Soucie | ... Miriam / Mona / Reporter (voice) |
| Christopher P. Walberg | ... Stinky (voice) |
| Sam Gifaldi | ... Sid (voice) |
| Justin Shenkarow | ... Harold (voice) |
| Blake Ewing | ... Eugene (voice) |
| Olivia Hack | ... Rhonda (voice) |
| Anndi McAfee | ... Phoebe (voice) |
| James Keane | ... Mr. Green / Riot Cop (voice) |
| Elizabeth Ashley | ... Mrs. Vitello (voice) |
| Michael Levin | ... Ray Doppel (voice) |
| Steve Viksten | ... Oskar (voice) |
| Dom Irrera | ... Ernie (voice) |
| Baoan Coleman | ... Mr. Hyunh (voice) |
| Craig Bartlett | ... Brainy / Murray / Grubby / Monkeyman (voice) |
