Justin Long
Humphrey (voice)
Hayden Panettiere
Kate (voice)
Dennis Hopper
Tony (voice)
Danny Glover
Winston (voice)
Larry Miller
Marcel (voice)
Eric Price
Paddy / Mooch (voice)
Chris Carmack
Garth (voice)
Kevin Sussman
Shakey (voice)
Brian Donovan
Salty (voice)
Christina Ricci
Lilly (voice)
Elizabeth Tulloch
Sweets (voice)
Christine Lakin
Reba (voice)
Mindy Sterling
Debbie (voice)
Fred Tatasciore
Garn (voice)
Nika Futterman
Porcupine (voice)
Steve Vinovich
Park Ranger (voice)
Aziz Ansari
Thug (voice) (uncredited)
Marilyn Tokuda
Claws / Janice (voice)
Maya Kay
Bear Cub (voice) (as Maya Feltheimer)