Judging by this AV Club interview, anyway:
And to the credit of the rest of the cast, I so much play off of their reactions. They give me so much. For instance, Jake Johnson, who’s so great and plays Nick on the show, when we did the pilot… [Laughs.] He would always give me these looks during scenes like, “What are you doing?” But in, like, an “I can’t believe I’m best friends with you” kind of way, which allowed me to go a little off the charts and continue to go in that direction. So I think the character has been totally informed by everybody.
Also, is it just me, or did someone Photoshop his mole out in that picture?