Peter Hastings Dog Man / Officer Knight / Harold's House (voice) Pete Davidson Petey the Cat (voice) Lil Rel Howery Chief (voice) Isla Fisher Sarah Hatoff (voice) Ricky Gervais Flippy (voice) Poppy Liu Butler (voice) Stephen Root Grampa (voice) Billy Boyd Seamus (voice) Luenell Milly (voice) Laraine Newman Scientist (voice) Melissa Villaseñor Realtor (voice) Cheri Oteri Mayor (voice) Kate Micucci Dippy (voice) Maggie Wheeler Nurse (voice) Rahnuma Panthaky Doctor (voice) Percy Rustomji Surfer (voice) Kevin McCann Grump (voice) Jana Schmieding Janet (voice) John Eric Bentley Living Spray Factory (voice) Warren Sroka Apartment Building (voice) Kimberly Bailey Gym (voice) Skip Stellrecht Ice Cream Building (voice) Cam Clarke Indifferent Shop (voice) Scott Menville 3D Guy (voice) Kelly Stables Harold (voice)