Ryan Reynolds

Jerry Hickfang / Mr. Whiskers (voice) / Bosco (voice) / Deer (voice) / Bunny Monkey (voice)

Gemma Arterton

Fiona

Anna Kendrick

Lisa

Jacki Weaver

Dr. Warren

Ella Smith

Alison

Paul Chahidi

Dennis Kowalski

Stanley Townsend

Sheriff Weinbacher

Adi Shankar

John

Sam Spruell

Dave

Valerie Koch

Jerry's Mother

Gulliver McGrath

Jerry (12 years old)

Paul Brightwell

Jerry's Stepfather