Mickey Mouse was created as a replacement for Oswald the Lucky Rabbit, an earlier cartoon character created by the Disney studio for Charles Mintz, a film producer who distributed product through Universal Studios. In the spring of 1928, with the series going strong, Disney asked Mintz for an increase in the budget. But Mintz instead demanded that Walt take a 20 percent budget cut, and as leverage, he reminded Disney that Universal owned the character, and revealed that he had already signed most of Disney's current employees to his new contract. Angrily, Disney refused the deal and returned to produce the final Oswald cartoons he contractually owed Mintz. Disney was dismayed at the betrayal by his staff but determined to restart from scratch. The new Disney Studio initially consisted of animator Ub Iwerks and a loyal apprentice artist, Les Clark, who together with Wilfred Jackson were among the few who remained loyal to Walt. One lesson Disney learned from the experience was to thereafter always make sure that he owned all rights to the characters produced by his company.