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John Ratzenberger
John Dezso Ratzenberger (born April 6, 1947) is an American actor, comedian and director. He is best known for playing the character Cliff Clavin on the comedy series Cheers, for which he earned two Primetime Emmy nominations. He also played a role in the short-lived spin-off The Tortellis and in an episode of Wings, which was made by the same creators. Ratzenberger voiced various characters in Pixar Animation Studios' feature films, including Hamm in the Toy Story franchise, The Abominable Snowman in the Monsters, Inc. franchise, Mack in the Cars franchise, The Underminer in The Incredibles franchise, and many others.
Ratzenberger began his entertainment career while living in London in the 1970s. He acted in and wrote film and television through the 1970s and early 1980s before returning to America. At an audition for a role in a new sitcom, Ratzenberger created the character of know-it-all mailman Cliff Clavin. Cheers (1982–1993) was a success and went on to run for 11 years. After Cheers, he began acting in voice roles for Pixar; his first role was as Hamm in Pixar's first feature film Toy Story (1995), and voiced other Pixar characters in every film and video game until 2020.
Source: Wikipedia