sentences:  Celebrities who have voiced themselves include Michael Buffer, Brent Musburger, Jay Leno, Robert Smith, and the bands Radiohead and Korn.Comedy team Cheech & Chong voiced characters representing their likenesses for the season four (2000) episode "Cherokee Hair Tampons", which was the duo's first collaborative effort in 20 years.Malcolm McDowell appears in live-action sequences as the narrator of the season four episode "Pip".