In spring 1928, Disney was removed from the Oswald series, and much of his staff was hired away to Winkler Pictures. He promised to never again work with a character he did not own. Disney asked Iwerks, who stayed on, to start drawing up new character ideas. Iwerks tried sketches of frogs, dogs, and cats, but none of these appealed to Disney. A female cow and male horse were created at this time by Iwerks, but were also rejected. They later turned up as Clarabelle Cow and Horace Horsecollar. Ub Iwerks eventually got inspiration from an old drawing. In 1925, Hugh Harman drew some sketches of mice around a photograph of Walt Disney. Then, on a train ride back from a failed business meeting, Walt Disney came up with the original sketch for the character that was eventually called Mickey Mouse. Afterward, Disney took the sketch to Iwerks. In turn, he drew a more clean-cut and refined version of Mickey, but one that still followed the original sketch.