Jennifer Coolidge is the kind of actress who lends a bucketful of originality to every character she inhabits. She made young boys sweat as Stifler’s hot mom in the American Pie trilogy, sweetened up the screen as a semi-naïve manicurist in the Legally Blonde films and, in some of her best work to date, constantly made audiences laugh as part of Christopher Guest’s ensemble casts in movies such as Best in Show and A Mighty Wind.

This month, however, she steps into the land of animation as a fun-loving robot with a rather large derriere in director Chris Wedge’s technological masterpiece, Robots.

"I’m so glad I was chosen. I think if you said you could pick any character you wanted to play, I would have chosen that one for myself," says Coolidge of her Robots character, Aunt Fanny. "I was hoping the ass would even be bigger. I like that she had … you know, you don’t get to see that very often, where they really, really give you an ass. It’s kind of nice."

In the film, which opens nationwide March 11, a genius robot named Rodney Copperbottom (Ewan McGregor) journeys to Robot City to fulfill his wildest dreams of becoming an inventor and, simultaneously, finding the iconic Bigweld (Mel Brooks). Once in Robot City, Rodney also finds love in the ultra-shiny Cappy (Halle Berry), a female ’bot with a polished, upgraded exterior who, much like Rodney, also hails from a working-class family. Heroes and villains also inhabit Robot City, as well as Aunt Fanny who, in her cozy home, houses the "Rusties," a group of robots who are afraid of being sent to the scrap heap at the hand of an evil businessman (Greg Kinnear) and his demonic mother (Jim Broadbent).

Aside from being somewhat matronly, Aunt Fanny – who has no idea about the true scope of her rear end and, therefore, continuously knocks things over in her own apartment – does end up being the love interest of one of the film’s other key robots.

"That’s kind of a good message. The girl with the big ass does get the guy in the end," says Coolidge, who makes her animated feature debut in Robots. "And you know what? I wanted the voice to reflect the ass. I mean, when I saw the ass I kept thinking, like, what would that sound like if it could speak?"

Apparently it would sound like Coolidge, who, when she originally went in to read for the part, wasn’t exactly sure what to do for the filmmakers.

"When they have you come in, you don’t really know if you have the job or not. I kept thinking, if the voice I came up with wasn’t what they were looking for, they just wouldn’t use me," she says. "So I kept trying to think of, like, what a big, round ass would sound like. I did these matronly voices first and they (the producers) were sort of lukewarm on those, and then I did a sexier voice that seemed to work better."

According to Coolidge, though, the end result – which, in her case, meant scoring the role of Aunt Fanny – turned out a little bit differently than she originally envisioned.

"I’ve never been in an animated feature film before so I really did think that I was going to be hanging out with Ewan McGregor (the voice of Rodney) and having salads together," says the actress, adding that doing an animated film is a bit lonely because you perform alone in a little dark booth. "But the cool thing is they do put a video camera on you and they catch a lot of your facial expressions and stuff. So when you watch the final product, the animated character has all your stuff, which is very smart I think.

The result was a character that audience members can instantly recognize as having Coolidge’s signature sound. The actress – who worked as part of L.A.’s popular Groundlings Comedy Group for nearly 10 years after waitressing and trying to gig in New York – brings her own special blend of quirkiness and comic timing to every role she inhabits. Most recently she’s managed to breathe life into Matt LeBlanc’s outrageous agent, Bobbie, in his NBC "Friends" spin-off, "Joey."

According to Coolidge, she made her character larger-than-life because her role on "Joey" was originally meant to be a short-lived gig.

"I thought it was a one-week thing, and I was like, I’m going to do something totally different. And I’m going to do this big, over-the-top character and then, cut to, they say, we’re going to make you a regular," she says. "Then I’m like, I’m going to be doing this every week. I would have picked someone a little bit more real, more normal. I don’t think I would have gone that far out with my character."

"Joey," Robots and all of her other film and TV roles aside, though, Coolidge admits that creating her characters is really quite simple.

"Usually you remember the people that were really hideous to you, and those are the people that usually make the best characters because you remember them so well. And there are a lot of people in this town that are hideous," she says, pointing to a time when she auditioned for the show "Silk Stalkings" and the casting director was extremely rude to her. "I mean, that ‘Silk Stalkings’ show, I auditioned for that, like, eight years ago. And I can remember her as clear as a bell, the things she said."

Robots releases in theaters March 11.