Bob Peterson

Roze (voice)

Bobs Gannaway

Roto (voice)

Stephen Stanton

Smitty / Needleman / Sanderson (voice)

Dee Bradley Baker

Banana Bread (voice)

Nathan Fillion

Johnny (voice)

Roxana Ortega

Celia Mae (voice)

Aubrey Plaza

Claire (voice)

Sander Argabrite

J.J. (voice)

Bobby Moynihan

Chet (voice)

Alanna Ubach

Cutter / Rosie / Maria (voice)

Christopher Swindle

Fungus / Ted / Phlegm (voice)

Paula Pell

Sunny (voice)

Rania Sharkawy

Avani (voice)

Richard Ayoade

Declan (voice)

Janelle James

Joy (voice)

Romi Dames

Hazel / Addie (voice)

Nohely Quiroz

FearCo. Receptionist / Adult Monster (voice)

Max Mittelman

Kenny / Brian (voice)

Natalie Lashkari

Monster Kids (voice)

Dan Molina

Ethan (voice)

Billy Crystal

Mike (voice)

Ben Feldman

Tylor (voice)

Mindy Kaling

Val (voice)

Henry Winkler

Fritz (voice)

Lucas Neff

Duncan (voice)