Cristin Milioti

Grace

Delaney Quinn

Freddy

Topher Grace

Ben

Keegan-Michael Key

Buddy the Unicorn (voice)

Michael Shannon

Willie (voice)

Patton Oswalt

Strappy (voice)

Clint Howard

George

Eric Bauza

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

Sergey Zhuravsky

Buddy the Unicorn (suit)

Jonathan Yurco

Dark Buddy (suit)

Devon Hawkes Ludlow

Charlie the Train (voice)

Jimmica Collins

Betty Bunny (voice)

Madison Polan

Hannah

Bryson JonSteele

Derek

Seamus Flynn

Timothy