When Albert Brooks was first approached to play Paul Rudd’s father in This Is 40, he couldn’t quite believe his ears.

Brooks, 65, still feels in the prime of life, thanks to young kids: a son, 14, and daughter, 13. Wife is artist Kimberly Shlain.

“It scared the hell out of me. I kept thinking, ‘Is this a science fiction movie?’ ’’ the Beverly Hills native says by phone. “I kept asking, ‘Should I have a cane? Are you sure you don’t want Mel Brooks?!’ ”

Fortunately, the filmmakers won out and got Brooks, who is well known for his lovably neurotic roles in movies like Broadcast News, Mother, Lost in America and The Muse.

“Everyone shows up for Judd,’’ Brooks says of the film’s director Judd Apatow.

Brooks is not one to be typecast. In recent years, he’s showed up as the memorable baddie in such films as Out of Sight and last year’s Ryan Gosling sleeper Drive. He loved changing things up.

“I like creepy,” Brooks admits. “There were a couple of villains I had my eye on playing over the years.” But American directors and casting agents were hesitant, knowing his resume.

Drive’s director, Nicolas Winding Refn, is Danish, and had no preconceived notions about his supporting actor (who got a Golden Globe nomination, by the way).

“I know what I’m capable of, and he did too,” Brooks says. “He said, ‘Why not? Let’s do this.’ He didn’t have a problem with it, and the audience didn’t either. It was noir at its best.”

Those same audiences may not have been the ones to turn out for Brooks’ animated 2003 classic, Finding Nemo, which was recently re-released in 3D and on Blu-Ray a few weeks ago. Brooks — who voices the single father clownfish who loses his son in the vast ocean — thinks the movie gets better with time.

“It’s so visually stunning,” he says, adding that a sequel is highly possible. “I’m hearing the rumblings.”

Voice work is way different from the in-the-flesh variety.

“Your brain and vocal quality have to be on extra high. You have to be on edge,” he explains, adding, “But you can be unshaven and come in in your pajamas.”

Madeleine Marr