Cliff Clavin

Cliff Clavin is a Boston mailman and Cheers barfly with an opinion on everything, whether or not it's true. He holds court from his stool, dispensing trivia — real, mangled, or invented on the spot — with total confidence, and treats his postal career as a matter of near-civic importance.

Ratzenberger built Cliff from a single audition-room improvisation about mail, and the writers ran with it: a blowhard whose bottomless certainty is funnier than any actual joke he tells. He's the bar's built-in laugh line, but there's real affection underneath the buffoonery, which keeps him lovable rather than just loud.