Walt Disney Studios Pluto Cartoons

Mickey's dog Pluto has appeared in nearly fifty cartoons. Pluto first appeared in 1930's The Chain Gang. He remained a relatively minor character until 1934's Playful Pluto.

Pluto was the first major Disney character to break out of the rubber-hose animation style so common in the twenties. Pluto had a real dogs form, and moved as a canine normally would. With his more realistic build, Pluto broke out of the anthropomorphized animal model so common in cartoons of this era.

As to who came first, the dog or the planet, there is no debate. The planet was discovered by Clyde Tombaugh on February 18, 1930, and officially named on March 24, 1930. The pup first appeared exactly six months later on August 18, 1930, and was not actually named "Pluto" until May 8, 1931 (with the release of The Moose Hunt). So the planet had the name- officially- first, and you can be assured the planet was named after the Roman god of the underworld, not the Disney cartoon character.