The exclusivity of animation also resulted in the birth of a sister industry that was used almost exclusively for motion picture special effects: stop motion animation. In spite of their similarities, the two genres of stop-motion and hand-drawn animation rarely came together during the Golden Age of Hollywood. Stop-motion animation made a name for itself with the 1933 box-office hit "King Kong", where animator Willis O'Brien defined many of the major stop motion techniques used for the next 50 years. The success of "King Kong" led to a number of other early special effects films, including "Mighty Joe Young," which was also animated by O'Brien and helped to start the careers of several animators, including Ray Harryhausen, who came into his own in the 1950s. George Pal was the only stop-motion animator to produce a series of stop-motion animated cartoons for theatrical release, the "Puppetoon" series for Paramount, some of which were animated by Ray Harryhausen. Pal went on to produce several live-action special effects-laden feature films.