Takamoto left Disney in 1961 and joined Hanna-Barbera shortly afterwards. He did many jobs there, but is probably best known as a character designer. He was responsible for the original character designs of such characters as Scooby-Doo, "The Jetsons'" dog Astro, and Penelope Pitstop. He worked as a producer at Hanna-Barbera, supervising shows such as "The Addams Family", "Hong Kong Phooey", and "Jabberjaw". He directed several feature-length animated films, including "Charlotte's Web" (1973) and "Jetsons: The Movie" (1990). The inspiration for Scooby-Doo's creation as a Great Dane came from an employee of the Hanna-Barbera company who bred this dog.