Christopher Mintz-Plasse as Ato, a happy-go-lucky beagle in a can. He puts up the Canimals logo between "The" and "Movie" at the beginning, and he appears during the entire movie except for the Credits.
Cristina Pucelli as Oz, a cat in a can. She disguises herself as a nurse in the "Medical" scene when Pow breaks his leg, and in the 20th Century Fox logo at the beginning where she sings along with the 1997 Fox fanfare arrangement.
J. W. Terry as Pow, an owl in a can. He appears in the "Medical" scene where Oz fixes his leg, and during all of the credits.
Christina Leah as Mimi, a loving poodle in a can. He is during the credits to scroll at the black background between the logo.