Jack Corbett

as Billy 5000 (voice)

Miya Folick

as Rosario 'Rozebud' Dolphin (voice)

Tavi Gevinson

as Glarba (voice)

Elsie Fisher

as Beatbox (voice)

Grace Kuhlenschmidt

as Freckles (voice)

Julio Torres

as T-Bone / Gas Station Guy / Brontosaurus (voice)

Joe Pera

as Herschel Cretaceous (voice)

Sarah Sherman

as Miss Sharon / Minivan Mom (voice)

Cole Escola

as Ol' Slippy / Nan (voice)

Eva Victor

as Gail 5000 (voice)

Chris Fleming

as Weenie (voice)

River L. Ramirez

as Gordon Spaghetti / Fettuccini Enthusiast / Paramedic / Minivan Baby (voice)

Max Wittert

as Byron (voice)

Janeane Garofalo

as Dr. Dolphin (voice)

Demi Adejuyigbe

as Mr. Moolah (voice)

J.R. Phillips

as Peanut (voice)