Mickey Mouse is an anthropomorphic cartoon character, and the most famous creation of Walt Disney.
Mickey Mouse made his first sound animated appearance in Steamboat Willie (1928). This was not Mickey's first cartoon, but as it was the first produced with sound and the first to be distributed, it is usually credited as being the first Mickey Mouse cartoon.
Mickey's girlfriend is called Minnie Mouse, his dog is Pluto and his nemesis is the oft-overlooked Donald Duck.