Conan O'Brien, a frequent writer behind the Simpsons, also guest starred on The Simpsons as himself during season five.

The Simpsons Season 5 Episode 12 Quotes

Bart: (Whistling Simpsons' Theme)
Marge: Bart, I've asked you not to whistle that annoying tune.
Bart: (Saluting and speaking German) Ja wohl, mein mamadant!

I didn't do it!