Dr Nick Riviera is a recurring character in the animated series The Simpsons, voiced by Hank Azaria and introduced in the early 1990s as a cheerfully incompetent doctor. His entrance line became a running gag, with Springfield residents answering in unison whenever he appears in a waiting room or public place. The exchange was repeated across many episodes and later circulated online as a short reaction clip, quoted in forums, remixes and fan edits. Its lasting appeal comes from that built in audience response, which makes even a two second greeting feel communal.