Peter Hastings as Dog Man / Officer Knight / Harold's House (voice)

Pete Davidson as Petey the Cat (voice)

Lil Rel Howery as Chief (voice)

Isla Fisher as Sarah Hatoff (voice)

Lucas Hopkins Calderon as Li'l Petey (voice)

Ricky Gervais as Flippy (voice)

Poppy Liu as Butler (voice)

Stephen Root as Grampa (voice)

Billy Boyd as Seamus (voice)

Luenell as Milly (voice)

Laraine Newman as Scientist (voice)

Melissa Villaseñor as Realtor (voice)

Cheri Oteri as Mayor (voice)

Kate Micucci as Dippy (voice)

Maggie Wheeler as Nurse (voice)

Pearce Bunting as Cheesesteak Guy (voice)

Max Koch as Rocco (voice)

Rahnuma Panthaky as Doctor (voice)

Brian Hopkins as Big Jim (voice)

Yung Gravy as Mr. Whiskers (voice)

Percy Rustomji as Surfer (voice)

Kevin McCann as Grump (voice)

Karen Foster as Robot (voice)

Jana Schmieding as Janet (voice)

John Eric Bentley as Living Spray Factory (voice)

Sonny Onorati as Radio Building (voice)

Warren Sroka as Apartment Building (voice)

Kimberly Bailey as Gym (voice)

Skip Stellrecht as Ice Cream Building (voice)

Georgia Simon as Hospital (voice)

Cam Clarke as Indifferent Shop (voice)

Scott Menville as 3D Guy (voice)

Kelly Stables as Harold (voice)