Dead Parrot Sketch
The "Dead Parrot Sketch" was a famous comedy sketch from the television series Monty Python's Flying Circus.
The Sixth Doctor once showed Mathew Sharpe the episode of the series that contained the sketch. As Mathew was not human and did not originate from N-Space, he didn't find the sketch funny, claiming that he didn't understand 20th century humour and finding himself concerned for the wellbeing of the titular parrot.
Eric Drazen called Mathew a "monster" for not laughing at the sketch, proving that its popularity endured even in the 32nd century. (AUDIO: The Lure of the Nomad [+]Loading...["The Lure of the Nomad (audio story)"])