Monsters University is a prequel to¬†2001’s Monsters, Inc. It is also basically Pixar’s remake of Revenge of the Nerds. The story finds Mike (voiced by Billy Crystal) and Sulley (voiced by John Goodman) as college freshman, forced to join the least popular fraternity on campus. And, as we all know, every ‘animal house’ needs an animal. In this case it is the impossibly proportioned Art, voiced by It’s Always Sunny in Philadelphia‘s Charlie Day. I sat down with Day in a screening room inside The Steve Jobs Building, the mothership of Pixar’s Emeryville, California campus.

Josh: This is your first animated feature, right?

Charlie Day: This is the first one that I’ve been in. I’ve seen a few.

Josh: So, what is the process for getting involved with an animated movie for hip, happenin’ guy such as yourself? Did Pixar come to you?

Day: In this particular circumstance they came to me. [Pixar] were fans of Always Sunny, and they had this idea for a character and they wanted him to sound like, well, like me. So they just called me up. And I said “yes.” Of course.

Josh: I would too. As your star, so to speak, has been rising the past few years, especially after Horrible Bosses, were you ever thinking to yourself, “Gee, I wonder if Pixar or Dreamworks or someone will call me up to do a voice in something”?

Day: It had not crossed my mind. Though I had always wanted to do a voice. I always felt that I had a very unique voice. But I assumed that people didn’t necessarily want to listen to it for two hours. No, you don’t want to be presumptuous about what you can or can’t do.

Josh: How old is your kid?

Day: One and a half. So he’s not quite ready for this.

Josh: Too scary?

Day: I think maybe I can show him a Youtube clip. But that’s probably all he can sit through.

Josh: When they brought you in, was the character of Art already designed?

Day: Yeah. They had drawn the character and they had animated a sequence using a clip from Always Sunny, a scene where I’m cleaning up a high school hallway. It was all done by the time I got here.

Josh: And you were like, “Yup. Looks good.”

Day: “Yeah, fine by me guys!” I just had to say their words.

Josh: What are your impressions of Art’s design? He reminds me a lot of pre-Muppet Show era Muppets.

Day: Somewhere between a Muppet and Grimace from McDonald’s, that is where you’ll find Art.

Josh: You get a lot of scene-stealing lines in the film. How much of Art was ad-libbed?

Charlie-Day-Interview-Monsters-University-VideoDay: People will probably give me credit for a lot of the one-liners, none of which I actually came up with. I really didn’t do any ad-libbing. I thought that is maybe what the process was gonna be, but they had really funny absurd non sequiturs for me to say every time I walked into the booth. I just said their lines. I didn’t know enough of the whole movie to ad-lib. They just told me what I was doing in the moment, they explained the scene, so for me to just say a line here and a line there — there wasn’t much room for ad-libbing. I presume Billy [Crystal] and John [Goodman; who recorded their dialogue together] did some ad-libbing. But I didn’t have to. They know how to write some funny stuff up here.

Josh: So they didn’t give you a full script. In the pages that they gave you, did they have multiple alternates for each line? Were the writers around, feeding you extra lines?

Day: They had alternate lines for things. There would be a sequence, and I would have some one-liners at the end. And they would have three or four different versions. But usually they had one that was their favorite, so I would try it several different ways, several different speeds. Then I would do the alts.

Josh: It is interesting. I would’ve bet good money that the line “I can’t go back to jail” was a Charlie Day ad-lib.

Day: No! And after they had me say that line I thought, “They’re never going to put this in the movie.”

Josh: Switching gears. Always Sunny got renewed for two more seasons, correct?

Day: We’re in the middle of shooting the ninth season — almost done shooting. Then we’ll start cutting that together end of summer, and get it out to everyone in the fall. Feel good about everything so far. As usual we have some episodes that feel typical to Always Sunny, and then we have some that are off-the-wall and will hopefully surprise the audience. Then we’ll do the 10th season. Either we’ll wrap it up, or, if FX wants to keep going, maybe we’ll just keep going.

Josh: Do you have an end in sight, in your own minds? Or do you think you’ll be like Trey Parker and Matt Stone and just keep running with Always Sunny forever?

Day: Well, one of the beauties of only doing ten episodes a year is that we can really focus in on them, and we don’t get burned out. If we were doing fifteen to twenty a year, by this point we’d be sick of things. Now we get to step away from the characters, and by the time next year rolls around it is nice to come back to them. As long as we can keep improving on the show and making people laugh, or at the very least keep surprising them — then, yeah, we’ll just keep doing it.

Josh: Speaking of these surprises, having Mac gain weight in Season 7 definitely felt like you guys were thinking outside the box to keep things fresh, at least for yourselves. Do you have anything high-concept planned for this upcoming season?

Day: We always do an episode or two to shake it up. Last year we did “The Maureen Ponderosa Wedding Massacre” to try one that is a higher-concept idea and execution. This year we have a couple episodes to shake things up. In the sixth season we did a Lethal Weapon 5 spoof. That was so much fun to shoot that this season we’re doing Lethal Weapon 6.

Josh: You’ve written so much of Always Sunny. Are you working on a screenplay? Or is it hard to find the extra time with the acting gigs you’ve been getting recently?

Day: There isn’t a ton of time for that. We would need at least half a year, or even a full year to write –

Josh: When you say “we” you’re referring to the Always Sunny crew?

Day: Yeah. Or even just one of us. I re-wrote a film that was at WB. Glenn [Howerton] and I were writing a western, until Seth MacFarlane beat us to the punch. So that slowed that down. Rob [McElhenney] has written something which is more of a higher-concept movie and is less of a comedy. I know we all want to write a film together, we just need the time. If the show ends with the tenth season, then we will most likely write a feature.

Josh: Before I let you go I probably have to ask something about Pacific Rim. Though I assume you can’t actually tell me anything.

Day: What do you want to know?

Josh: Ah, don’t tease me like that. If there is a sequel, would you be coming back?

Day: I’ll scratch and claw to make sure I come back. It was so much fun to make. But they’ll obviously only do a sequel if people turn out. Or we’ll have to start the world’s biggest Kickstarter!

Josh: Hey, can we have $250 million please?

Day: Just a $250 million Kickstarter.

Josh: Knowing what I know about Del Toro, I have to assume that there is so much more to the movie than what we see in the trailers.

Day: Oh yeah. That is just a taste of the action and scale. It is a beginning to end orgy of optical and sound creativity. I think people are going to have their minds blown.