Mickey Mouse was created as a replacement for Oswald the Lucky Rabbit, an earlier cartoon character that was created by the Disney studio but owned by Universal Pictures. Charles Mintz served as a middleman producer between Disney and Universal through his company, Winkler Pictures, for the series of cartoons starring Oswald. Ongoing conflicts between Disney and Mintz and the revelation that several animators from the Disney studio would eventually leave to work for Mintz's company ultimately resulted in Disney cutting ties with Oswald. Among the few people who stayed at the Disney studio were animator Ub Iwerks, apprentice artist Les Clark, and Wilfred Jackson. On his train ride home from New York, Walt brainstormed ideas for a new cartoon character.