 The staff was able to get the central cast of the American sitcom Cheers , with the exception of <unk> Grammer , to reunite and guest star in the episode . The staff could not arrange the script to allow time in the episode for Grammer , who already had a recurring role on The Simpsons as Sideshow Bob , to voice <unk> Crane . Ted <unk> guest starred as Sam , Woody <unk> as Woody , Rhea <unk> as Carla , John Ratzenberger as Cliff , and George <unk> as <unk> . 
