Dr. Seuss’ The Lorax (opening in theaters on March 2^nd), is the beloved children’s story that’s also its author’s favorite work. The 3D-CG animated adaptation is an adventure that follows the journey of idealistic 12-year-old Ted (voiced by Zac Efron) while he searches for a real Truffula Tree for Audrey (voiced by Taylor Swift), in order to win the affection of the girl of his dreams. To find one, he must learn the story of the Lorax (voiced by Danny DeVito) from the enigmatic and bitter old hermit, known as the Once-ler (voiced by Ed Helms), who let the temptation of greed and success get the better of him.

At the film’s press day, actor Ed Helms spoke to Collider for this exclusive interview about how he pursued being a part of the film, that he was stunned when he was offered the role of the Once-ler, finding the voice for each of the different stages and ages of the character, and how cool it was to get to sing and play guitar on the film’s original songs (he has his on bluegrass trio and has been wanting to record an album of his own, for some time). He also talked about his next feature film, Jeff Who Lives at Home (due out in theaters on March 16^th), which he is clearly very proud of, the current status of The Hangover 3, and how much fun he’s been having as the office manager on the NBC comedy series The Office. Check out what he had to say after the jump:

Collider: How did voicing an animated Dr. Seuss character come about for you?

ED HELMS: I pursued it, actually. I made my interest known, very early on. I’m a big fan of Illumination and what they’ve done. I loved Horton Hears a Who, and Despicable Me with Steve [Carell]. So, when I heard that The Lorax was on their agenda, I asked for a meeting with Chris Meledandri, who I actually knew from some writing work I’d done for the director of Ice Age, years ago. I met with Chris and told him, “This book had a special spot on the bookshelf when I was a kid and I loved it and I would be psyched to just be a part of it, in any way. No matter how big or small, I’d just be thrilled to be on board.” And then, a couple months later, they were just starting to get the cast together and I got the offer for the Once-ler and I was actually stunned. I did not expect that.

As a fan of this story, was it fun to play a character that you don’t actually get to see too much of, in the books?

HELMS: Yeah, it was absolutely a huge thrill, and also a very daunting task. The book, to me, was just inspirational source material. Really, when looking at how to do this character, it’s about the script that they gave me because he’s so much more fleshed out than anything that was in the book. I can only hope that I’ve approached something that Dr. Seuss, himself, might be happy with. I was really excited when I saw how this was expanded – how the world was expanded, the backstory for Ted, and the opportunity to play the Once-ler at what was really three stages of his life. That was something I’ve never done before, on camera or not, and was really fun. I also think they did a really good job making the Once-ler sympathetic. I felt that a big part of my challenge, voicing the character was to not make him one-dimensionally evil or bad, but as just a decent guy who went off track. They did a wonderful job in the script, setting that up.

Did you have a process for figuring out how you wanted the voice to be, for each incarnation of him?

HELMS: The hardest part was definitely finding that old Once-ler voice. I think I was cocky, going into it. I thought, “Oh, I’ll just do an old man voice.” But, it turns out that that doesn’t really sound like an old man. It just sounds like a guy doing an old man voice and doesn’t really have a lot of personality. It was really through a series of recording sessions that it started to come into focus, with how expressive he was and the way that the old Once-ler’s inflection was different from the young Once-ler. Aside from just the voice quality, it was a little bit more of a bitter, cantankerous energy. But, it was a really fun challenge and totally new to me. I’ve not done that kind of thing before.

Chris Meledandri said that you also being a writer was great because of your ease with ad-libbing, in the invention of the character. Did it feel like that gave you an advantage?

HELMS: Well, I just love creative collaboration. When I had lines in front of me, to me, that’s just a starting point. I get that done and then try to just riff on other ways to say the same thing, or clarify what’s in there. That’s just the fun of the creative process. It happens on The Office, all the time. It’s happened on all the movies I’ve been in. I like to really internalize. I’m not a method actor, by any stretch, but I do like to really try to think about where a character is coming from, once a personality is established. In the case of the Once-ler, he’s really kind of dorky, in the beginning. So, that was just fun. I’m so grateful for how open-minded and collaborative the director was.

Did you see any of yourself at all, in the final product?

HELMS: I’ve only seen it once, and I was just so blown away. The whole thing is just so visually stunning. It’s crazy! I couldn’t say, if I really felt like my facial movements are in there, but I’ll take a closer look. It was just such a thrill to see it. I love how expressive the old Once-ler is, even with just his eyes and hands. It’s really cool. That really communicates a lot. I think the thing I’m most proud of with this movie is that, if you look at this movie in a void, it’s a wonderful, fun experience, but it’s also just something that is part of the legacy of Dr. Seuss, which is just the most magical, wonderful legacy. I’m so proud to be even just a little, tiny part of it.

Since singing and playing the guitar are also a big part of the character, was it exciting to get to do that as well?

HELMS: It was very cool! It was really fun to see how the writers and Chris [Renaud], the director, were so open-minded about what I could bring to it and how that might influence the character of the Once-ler. So, the Once-ler’s singing and guitar playing became a bigger part of it, and I even worked in a little bit of banjo. It had nothing to do with the Once-ler, but I played a little bit of banjo in that “Let it Grow” number, at the end. If you listen really carefully, you can hear some banjo that comes in under when Betty White is singing. That was really cool.

Did it inspire you to want to do an album, or ask any of your celeb friends to collaborate on a song?

HELMS: Yes, I’ve been wanting to do an album for quite some time, and it’s coming into focus, more and more. I have a bluegrass trio, called The Lonesome Trio. We’ve been playing together for 17 years, since we were college buddies. We have a lot of great original tunes. The wheels are turning. I’m excited!

What was it like to have the experience of working on something like Jeff Who Lives at Home with Jason Segel, and both of you doing dramatic roles?

HELMS: I love that movie. I’m so proud of it. It’s such a weird little world that Mark and Jay Duplass created. We had so much fun making it, even though it’s not particularly funny. That was new territory for me, certainly, as a professional actor. In high school, I did “All My Sons,” but that was probably the last dramatic thing I did. But, man, Jason is a phenomenal actor. Obviously, he’s funny as hell, but he brought a lot of heart to Jeff Who Lives at Home. It was really fun, and a huge privilege just to bounce off that.

How much improvisation did you do on that film?

HELMS: Jason and I both come from a background of doing comedy and also improvising quite a bit, and we did, a lot. So much of Jeff Who Lives at Home is improvised dialogue. But, what’s really special about it is that we weren’t improvising comedy. Usually, improvisation is about finding the best joke or the silliest way to get something across. Improvising conflict is always fun because you can just go for it. But, Mark and Jay [Duplass] encouraged us to improvise so much, even in these very dramatic beats and scenes. Judy [Greer] and I have this big fight scene in a hotel room, and it’s really intense. She just dove right in, too. It’s an exciting way to make a movie.

What do you know about the status of The Hangover 3? Have you been given any updates about when you’ll start filming?

HELMS: Well, we don’t know if we’ll start filming yet, for sure. Honestly, we’re hopeful and excited, and I think there’s a lot of good energy around it, but we’re not over the finish line, as far as getting it done. But, as far as when it would happen, I don’t know. Really, if we can get everything sorted out, then I imagine it might go quickly, but I don’t really know.

Does that come down to the script or contracts, or something else entirely?

HELMS: I don’t know. I’m a little bit confused, myself. You know, getting any movie made is just like trying to push a giant boulder up a mountain, and there’s so many moving parts. Obviously, there’s the creative side, and then there’s the logistical side, and they’re both colossal. Hopefully, we’ll align them and get it going.

Will this be your last season on The Office, or are you still contracted for more?

HELMS: We’re not officially picked up for next season, by NBC. But, I’m super proud of the show and NBC has certainly been supportive. I think we’re all hopeful to do more great work on the show.

What’s it been like to get to be the office manager?

HELMS: It’s been a blast. I think I was anxious, coming into the season, but then on day one, it was like, “We’re all back. Here we go! We’re diving right in!” We have the best crew on planet earth, and the best cast, and everyone just works their ass off. I’m having a good time doing it. Once we’re there, there’s not a lot of second guessing, analysis, or over-thinking, in a good way. We’re just having a good time trying to be silly.

Are there things that you would like to see happen with your character or on the show, before it’s done?

HELMS: Yes, absolutely! There are those things, and I hope that I’ve been open about that, internally. I hope that some of those things align with the writers room’s hopes as well, but we’ll have to see.