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 the City'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. Either way, he gives Mickey his first TV Sketch.
Rover is also interested in rebuilding Tomorrow City and making it the place it once was. He congratulates Mickey on making a good choice if he follows the Paint path with the Slobber.
- 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.
- He is immune to TV Sketches, because he has seen the cartoons (or cartoon) shown so many times he just finds them boring.