John Dezso Ratzenberger (born April 6, 1947) is an American actor, voice actor, and entrepreneur. He is known for playing Cliff Clavin in the TV show Cheers, for which he earned two Emmy nominations. Ratzenberger is also known for his extensive voice roles in Pixar Animation Studios' films, such as Hamm in the Toy Story franchise and Mack in the Cars franchise. He is the only actor to appear in all of Pixar's feature films, and with minor appearances in major films such as Superman and The Empire Strikes Back, is one of the most successful actors of all time in terms of box-office receipts.
Born in Bridgeport, Connecticut, Ratzenberger began his entertainment career while living in London in the 1970s. He had minor film and television roles throughout the late 70s and early 1980s before landing the role of the know-it-all mailman Cliff Clavin on Cheers (1982–1993), a role he portrayed throughout the show's eleven seasons. His first Pixar role was the voice of Hamm the Piggy Bank in Toy Story (1995) and has voiced Pixar characters in films and video games ever since. From 2004 to 2008 he hosted the TV documentary series Made in America. Outside of acting, he has promoted American entrepreneurship and manufacturing, and campaigned for several Republican candidates.