After appearing on the inaugural broadcast of Saturday Night Live in 1975, Andy Kaufman became nationally famous as a comedian who provoked nervous laughter, if any at all. He impersonated Elvis Presley, read aloud from The Great Gatsby until the audience left in disgust, or touted himself as an "Intergender Wrestling Champion," fighting mostly women in what were seemingly real matches. He also co-starred in the hit TV series Taxi. Because it was hard to tell when Kaufman was kidding, even the news of his unexpected death was met with some skepticism.
Extra credit: Kaufman was played by comedian Jim Carrey in the 1999 film Man In the Moon.
