Jim Rash was such a scene-stealer in Dean's "sister's" costumes for the show's first two seasons, they made him a series regular this year. He's been Dean-ing things to a whole new level, facing off with guest stars John Goodman and Luis Guzman, singing 'Kiss from a Rose' with Jeff (Joel McHale) in mall karaoke and loving seeing his own insanity acted out when Jeff played him for Greendale's big new commercial.