By ANGELA DAWSON

Front Row Features

EMERYVILLE, Calif.—Monsters are very much a big part of Charlie Day’s life this summer.

The “It’s Always Sunny in Philadelphia” star plays a brilliant but somewhat offbeat scientist trying to conceive a way to stop alien monsters known as Kaiju from invading earth in Guillermo del Toro’s live-action sci-fi epic “Pacific Rim.” In the animated comedy “Monsters University,” the New York native voices the character of the strange and mysterious Oozma Kappa student Art.

The youthful looking 37-year-old was surprised and delighted when Pixar called him to voice the furry purple rainbow-shaped character that is part of the same underdog fraternity as Mike Wazowski (Billy Crystal) and James P. “Sulley” Sullivan (John Goodman). Though a supporting character in the hit movie, Day’s Art steals practically every scene he is in with his humorous non sequiturs. He also exhibits surprising dexterity in helping his frat team win the Scare Games.

His character in “Pacific Rim” is equally offbeat and similarly integral to the plot of that movie. His job as Dr. Newton Geiszler is to come up with a way to stop the deadly attacks of alien monsters that are destroying our planet. With his staccato dialogue, he provides a bit of comic relief as the smart but unconventional scientist.

During a recent interview at Pixar headquarters, Day spoke about his two roles and how a bad early work experience taught him to create his own work opportunities and be a better boss.

Q: Did you ever think you’d be in an animated movie?

Day: No. I didn’t think they let my kind in here.

Q: What happened?

Day: I don’t know. They’re running out of talent? (He laughs.)

Q: That’s the point of “Monsters University”—it takes all kinds, right?

Day: Yeah. It’s a melting pot. Even us basic cable people can get a job here.

Q: Had you seen your character Art before you auditioned? Did you know what he was going to look like?

Day: I had the good fortune of not auditioning, which was wonderful. The Pixar folks are big fans of “It’s Always Sunny in Philadelphia” and they invited me here and showed me a rendering of the character. He was doing all of his moves and they had animated him to lines from “It’s Always Sunny in Philadelphia” episodes.

Q: How strange was that?

Day: It was very weird. I felt as though they had made a mistake. But it was great. Art is funny and quirky and I realized it was going to be a real easy job. The animators were doing all the hard work.

Q: What’s his story? He’s in a frat with nerds, but he’s not a nerd.

Day: He’s more of a drifter, I think. I’m not even sure he’s actually a student at the college. He may be crashing there. Nobody knows his story. I assume he’s some sort of marsupial but I can’t tell. We just know that he’s a very happy-go-lucky guy. He’s an optimist but he has a mysterious past. And I guess he’s been incarcerated.

Q: Is he a stoner?

Day: Well, uh, I don’t know if they have that in Monstropolis. He may be eating some sort of cereal that makes him crazy.

Q: Do you see any of yourself in your character?

Day: No. I’m not nearly as flexible.

Q: You were pretty young when “Monsters, Inc.” came out, right?

Day: Not really. I was 25 years old. I look younger than I am.

Q: Did you see it at the movie theater?

Day: Yeah, and I happen to own the movie. I had just re-watched it shortly before I got the call to do the sequel. So maybe I need to watch some of Pixar’s other films.

Q: Who did you see the movie with?

Day: I saw it with my wife (actress Mary Elizabeth Ellis), who was my girlfriend at the time.

Q: What was your college experience like?

Day: There were fewer monsters. I went to a small liberal arts school (in Massachusetts). I went there to play baseball and not unlike the character of Mike, I soon realized I had some physical limitations and my baseball career wasn’t going to go any further. Then, I started to find myself a little bit, which was wonderful. I got more involved in the arts and became a better student when I began to study things I enjoyed. I got a degree in art history but also was doing as much theater as I could. That’s how I got started on the path that I’m on.

Q: Did the comedy come to you after you started acting or were you always a comedian?

Day: I always was a funny guy, the class clown. I had a very funny dad and an extremely funny grandmother, who passed away about a year ago. I started going to a place called the Williamstown Theatre Festival (in Massachusetts) where I was doing Tennessee Williams plays and anything else I could do. I also was doing episodes of “Law & Order” and “Third Watch” and I did TV commercials—just trying to make a living. It wasn’t until Rob McElhenney, Glenn Howerton and I decided to make “It’s Always Sunny in Philadelphia” that I started to do comedy for an audience of people. I love it. It’s always been a part of my nature but I didn’t set out to be strictly a comedian.

Q: Do you have trouble finding dramatic parts now because you’re known for being funny?

Day: I don’t know yet because most of my serious stuff I did before “It’s Always Sunny in Philadelphia” and (the comedy) “Horrible Bosses.”

Q: You’re character is funny in “Pacific Rim,” but the film is not a comedy.

Day: It’s funny at times, but I’m serious throughout a good chunk of the film. I’m a somewhat serious person in real life. The business of making “It’s Always Sunny in Philadelphia” is a serious business except between “action” and “cut.” But if the audience laughs at me, it’s fine. I’ll stick with that.

Q: Did you improvise some of your lines in “Pacific Rim”?

Day: I do have a joke or two, just by nature. You need a little bit of that in the film. It’s not unlike Jeff Goldblum’s character in “Jurassic Park.” He makes you laugh occasionally but you also worry whether or not he’s going to be eaten.

Q: Who you do you play in “Pacific Rim?”

Day: I play Dr. Newton Geiszler. I’m sort of an expert on the Kaiju, the monsters coming from the ocean. I’ve got some radical theories about how to stop them and I get in a little over my head in my attempts to follow through on those theories.

Q: Uh oh! Are you eaten?

Day: I won’t say. You’ll have to see the movie.

Q: What’s the story on “Horrible Bosses 2?” Are you going to be working with Jennifer Aniston, Jason Bateman and Jason Sudeikis again?

Day: I’ve agreed to be part of it solely for the opportunity to work with all of those people again. I know they’re talking to Jennifer and hopefully she’ll do it. They’re now rewriting the script and hopefully they’ll come up with something that is worth people’s time. Just like my (“Monsters University”) experience or working with del Toro (on “Pacific Rim”), for me it’s an opportunity to work with such great people, so hopefully everyone comes back and we make something fun.

Q: Before you were an actor, you tended bar. What’s your most memorable experience from those days?

Day: I was bar-backing in New York on St. Patrick’s Day. I showed up at 4 a.m. to open the place and then halfway through the day the guy that was supposed to relieve me called in sick and so I worked until 4 a.m. the next day, so I worked 24 hours straight. But the bartenders didn’t tip me. They made thousands of dollars that day and they didn’t tip me. So I quit. I was going to throw a brick through the window but I kept my cool. I just left. If anything, it inspired me to get out there and be my own boss—and treat my employees better.

Q: Any particular “Monsters University” toy you’re interested in having?

Day: I hope to get my hands on an Art doll so I can give it to my boy (Russell).

Q: Has he seen the movie?

Day: No. He’s only a year and a half but I think he’ll be able to make it through a few clips. Give him a couple of years.