Cristin Milioti

Grace

Delaney Quinn

Freddy

Topher Grace

Ben

Keegan-Michael Key

Buddy the Unicorn (voice)

Michael Shannon

Charlie the Train / Willie (voice)

Patton Oswalt

Strappy (voice)

Clint Howard

George (voice)

Eric Bauza

Mr. Mailbox / Worry Well / Couchy / Trashy / Pee Flower (voice)

Sergey Zhuravsky

Buddy the Unicorn

Madison Polan

Hannah