Disney's first creation was a cartoon character that he named Oswald the Lucky Rabbit. This rabbit realized some popularity, but Walt Disney still kept up his search for the right character he wanted. And, it was in 1928, when Walt Disney took a five-day train trip with his wife Lillian, that he came up with the idea of a cartoon mouse named Mortimer. It is said that Disney actually fashioned the mouse after Oswald the Lucky Rabbit. Whatever the case, his wife rejected the name of the mouse, and Disney ended up changing it from Mortimer to Mickey. When they arrived in California, Disney worked friend Ub Iwerks on creating Mickey Mouse. He made his debut on November 18, 1928, in a black and white cartoon called "Steamboat Willie."