Buddy

Cristin Milioti

Grace

Delaney Quinn

Freddy

Topher Grace

Ben

Keegan-Michael Key

Buddy the Unicorn (voice)

Michael Shannon

Charlie the Train (voice)

Patton Oswalt

Strappy (voice)

Clint Howard

Eric Bauza

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

Sergey Zhuravsky

Buddy the Unicorn

Madison Polan

Hannah

Bryson JonSteele

Derek

Seamus Flynn

Timothy