I was just fooling around with the piano and Todd [Phillips] was like, 'Hey there's a great spot in the movie [The Hangover] where we need a little bit of a breath in the narrative. You should write a song and stick it in there.' And I was like, 'Well, what should the song be about?' And he said, 'The tiger.' 'Oh, okay.' So I went off and I wrote this song. I came back and Todd and I tinkered with it a little more and then we shot it right then. It all happened in a day.

When you try hard at everything you do, even when it feels foolish to do so, you’re opening up doors and possibilities you might not be seeing in the moment.

Almost everything is in the movie [The Hangover]. I think the fun little Easter eggs on the DVD will be sort of the gag reel stuff. There's a lot of takes we just couldn't get through.We were laughing.

When I was 15 I lost a tooth and had an implant put in. Cut to 20 years later, I'm doing this part [Andy Bernard] and the script calls for my character to lose a tooth.

As an actor, you can really play the intensity and gravity and seriousness of the moment, and just rely on the circumstances being funny. The joke is kind of the situation you're in, or the way you're reacting to something, as opposed to the characters just saying something witty.

I'm pretty sure no one's reading action scripts saying, 'This has got to be Ed Helms.'

I mean they [ Bradley Cooper, Zach Galifianakis] are both just really good guys and also they're both extremely funny in very unique ways. We made each other laugh an awful lot, and that goes a long way. And we also went through some hard times. I mean it was hard to make this movie [The Hangover].