The Big Bang Theory [02/05/2015] - "The Troll Manifestation"

And the troll was --SPOILER-- Stephen Hawking. :) That was a fun twist.

Sheldon: Professor Hawking?

Professor Hawking: Oh, brother, you should see the look on your faces.

Leonard: You really didn't like our paper?

Professor Hawking: I like your paper very much. The premise is intriguing.

Sheldon: Then why are you attacking us?

Professor Hawking: If you were sitting in a chair for 40 years, you'd get bored, too. Anyway, got to go. I promised to help the neighbor kid with his math homework. Ciao.