"The Aristocrats" is a taboo-defying, off-color joke that has been told by numerous stand-up comedians since the vaudeville era.
[1] It relates the story of a family trying to get an agent to book their stage act, which is remarkably vulgar and offensive.
[2] When told to audiences who know the punch line, the joke's humor depends on the described outrageousness of the family act.
[6] The joke came to wider public attention when Gilbert Gottfried told it during the Friars' Club roast of Hugh Hefner to recover after losing the crowd and eliciting "booing and hissing" with a joke about the 9/11 terrorist attacks, which had occurred just 18 days prior.
[7] The 2005 documentary film of the same name by Paul Provenza and Penn Jillette featured numerous comedians discussing and retelling the joke.