With the coming of World War II, Superman was quickly enlisted in the war effort, fighting Japanese and German spies and saboteurs as well as the usual mobsters and mad scientists. This was true on both the page and the big screen, where Superman made his movie debut in 1941 in a series of animated shorts by Max and Dave Fleischer, the brothers behind the Popeye and Betty Boop cartoons. In these shorts were born such Superman catchphrases as "It's a bird! It's a plane!" and "Faster than a speeding bullet, more powerful than a locomotive, able to leap tall buildings in a single bound."