Meli Povenmire
Gretel (voice)

Michael Cimino
Kevin (voice)

Beck Bennett
Hamster (voice)

Joey King
Fred (voice)

Matt Jones
Dave (voice)

Carolina Ravassa
Carolina (voice)

Romi Dames
Hiromi (voice)

Liza Koshy
Veronica Hill (voice)

Priah Ferguson
Bailey (voice)

Phil LaMarr
Professor Exclamation (voice)

Pamela Adlon
Nordle (voice)

Brock Powell
Lyle (voice)

Alyson Stoner
Lauren (voice)

Cree Summer
Ms. Weems (voice) / Librarian (voice)

Carlos Alazraqui
Luchador (voice) / The Luchador (voice)

Dee Bradley Baker
Otter (voice)

Diedrich Bader
The Imposter (voice) / Arthouse (voice)

James Adomian
Rodney Thunderpants (voice)

Casey Hamilton
Mr. Chabner / Van Dyke (voice)

Michael-Leon Wooley
Roman (voice)