The character of Cliff Clavin was created for John Ratzenberger after he auditioned for the role of Norm Peterson, which eventually went to George Wendt. While chatting with producers afterward, he asked if they were going to include a "bar know-it-all", the part which he eventually played.[22] Alley joined the cast when Shelley Long left, and Woody Harrelson joined when Nicholas Colasanto died. Danson, Perlman and Wendt were the only actors to appear in every episode of the series; Ratzenberger appears in all but one (and his name wasn't part of the opening credit montage during the first season).