John Cleese (in-universe)

John Cleese was an entertainer and comedian associated with Monty Python.

Other realities
In one parallel universe, John Cleese also existed as an entertainer. In 1979, he was hypnotised by Beep the Meep. (COMIC: TV Action!)

Behind the scenes
John Cleese had a cameo in the Doctor Who television story City of Death, in which he portrayed an art lover.