Zwiastun
Obsada
Cristin Milioti
Grace
Eric Bauza
Mr. Mailbox / Worry Well / Couchy / Trashy / Pee Flower (voice)
Phuong Kubacki
Nurse Nancy
Tristan Borders
Oliver
Caleb Williams
Wade
Madison Polan
Hannah
Bennie Taylor
Mailman Miles
Luke Speakman
Josh
Delaney Quinn
Freddy
Keegan-Michael Key
Buddy the Unicorn (voice)
Cedwan Hooks
Betty Bunny (suit)
Rachel Appelbaum
Clocky / Mr. Mailbox (uncredited)
Sergey Zhuravsky
Buddy the Unicorn (suit)
Jonathan Yurco
Dark Buddy (suit)
Seamus Flynn
Timothy
Michael Shannon
Willie (voice)
Clint Howard
George
Jimmica Collins
Betty Bunny (voice)
Tory J. Malone
Tyler
Brooke Bloom
Dr. Deborah Burr
Noah Pierre D.
Jakson (uncredited)
Bryson JonSteele
Derek
Topher Grace
Ben
Patton Oswalt
Strappy (voice)
Eric Salazar
Grilling Man
Devon Hawkes Ludlow
Charlie the Train (voice)
Mark Aaron Buerkle
Therapist (Day Player)