John Ratzenberger is an American actor and voice artist best known for his role as Cliff Clavin on the popular TV show Cheers. His character, a mailman with a knack for trivia, became a beloved figure in the series, which aired from 1982 to 1993. Ratzenberger's performance earned him recognition and a loyal fan base. In addition to his work on Cheers, Ratzenberger has lent his voice to many characters in Pixar films, including Hamm the piggy bank in Toy Story and Mack the truck in Cars. His contributions to animation have made him a familiar voice for audiences of all ages.