Oswald the Lucky Rabbit Mouse cartoon to be filmed was "Plane Crazy" in the summer of 1928, but it was produced as a silent and held back from release. The first Mickey Mouse film with a synchronized soundtrack, "Steamboat Willie", reached the screen that fall and became a major hit, eclipsing Oswald. "Plane Crazy" was later given its own synchronized soundtrack and released on March 17, 1929. Mintz, meanwhile, opened his own studio consisting primarily of former Disney employees, where he continued to produce Oswald cartoons, among them the first Oswald with sound, "Hen Fruit" (1929). While things were going in Mintz's favor, animators
Oswald the Lucky Rabbit stories themselves became softer. Minor changes in the drawing style would continue, too. With "Happy Scouts" (1938), the second-to-last Oswald film produced, the rabbit's fur went from being all-white to a combination of white and gray. Unlike the Disney shorts, in which Oswald did not speak, Lantz's cartoons began to feature actual dialogue for Oswald, although most of the cartoons were still silent to begin with. Animator Bill Nolan did the voice of Oswald in "Cold Turkey", the first Lantz cartoon with dialogue, and the following year Pinto Colvig, who was working as an animator and gag man at the