- Umpired Little League baseball as a teen.
- While working in a video-rental store in Los Angeles, a customer asked for a movie that starred Sidney Poitier. Waters asked the man to spell the actor's name so he could look up the film. The customer was Sidney Poitier, as his manager later informed him.
- Was once part of the comedy duo Derek and Simon, with Simon Helberg, with whom he starred in the web series Derek & Simon: The Show.
- Was a member of the Upright Citizens Brigade.
- Appeared in two short films with Halberg, Derek & Simon: The Pity Card, and Derek & Simon: A Bee and a Cigarette.
- Co-creator and star of Drunk History.
- Has a Saturday Night Live script autographed by all the members of his favorite band, Pearl Jam.
- Has taken boxing lessons.