Spencer Klein as Arnold (voice)

Francesca Marie Smith as Helga Geraldine Pataki (voice)

Jamil Walker Smith as Gerald Johanssen / Rasta Guy (voice)

Dan Castellaneta as Grandpa 'Steely' Phil / Nick Vermicelli (voice)

Tress MacNeille as Grandma Gertie 'Pookie' / Mayor Dixie / Red (voice)

Paul Sorvino as Scheck (voice)

Jennifer Jason Leigh as Bridget (voice)

Christopher Lloyd as Coroner (voice)

Vincent Schiavelli as Mr. Bailey (voice)

Maurice LaMarche as Big Bob Pataki / Head of Security (voice)

Kath Soucie as Miriam Pataki / Mona / Reporter (voice)

Christopher Walberg as Stinky Petersen (voice)

Sam Gifaldi as Sid (voice)

Justin Shenkarow as Harold Berman (voice)

Blake McIver Ewing as Eugene Horowitz (voice)

Olivia Hack as Rhonda Wellington Lloyd (voice)

Anndi McAfee as Phoebe Heyerdahl (voice)

James Keane as Marty Green / Riot Cop (voice)

Elizabeth Ashley as Mrs. Vitello (voice)

Michael Levin as Ray Doppel (voice)

Steve Viksten as Oskar Kokoshka (voice)

Dom Irrera as Ernie Potts (voice)

Baoan Coleman as Mr. Hyunh (voice)

Craig Bartlett as Monkeyman (voice)