Mister Rover is an anthropomorphic dog who hosts the Great Big Tomorrow exhibit in Tomorrow City. He shows murals on the rotating theater stage depicting visions of Wasteland's future, which will vary depending on how Mickey chooses to deal with the Slobber. If Mickey redeems the Slobber with Paint, he'll be shown a mural depicting a beautiful and bright optimistic-looking scene. If Mickey defeats the Slobber with Thinner, he'll be shown a mural depicting a chaotic landscape.
- Mr. Rover owns a lost dog, whose tags can be found by Mickey to give to Horace for use in solving the mystery.
- His name is a reference to Rover, the family dog in the Carousel of Progress attractions at the Disney theme parks.