VIDEO: Jon Hamm Appears on 'Children's Hospital' Season Finale

Jon Hamm is making the rounds.

The Mad Men star, who recently hosted Saturday Night Live for the third time Oct. 30, made a cameo on Adult Swim's Children's Hospital season finale, which aired Nov. 7. The finale was dubbed as a "live episode."

Cast member Malin Akerman revealed at the very end of the episode that she wasn't exactly who she appeared to be. She then took off her "mask" and revealed herself to be Hamm.