Bad, Bad, Bad Bobcat!

Leave it to renegade comedian Bobcat Goldthwait to find a way to break the law even while proposing to his girlfriend, actress Nikki Cox.

“Just before my mom passed away recently, she said, ‘Hurry up and ask that girl to marry you,’ ” Goldthwait said by phone recently from his Los Angeles area home. “So the night of my mom’s funeral, my brother and I spray-painted, ‘Will you marry me?’ on the bridge near my old high school [in Syracuse, N.Y.].

“The bridge had so much graffiti on it,” he added, “that we had to put a primer coat down! I said, ‘If we get caught right now, we’re going to tell the police that we’re just cleaning [up the old graffiti].’ ”

The 37-year-old stand-up comic and actor, who appears tonight at the Coach House in San Juan Capistrano, is no stranger to outrageous and sometimes illegal behavior.

A court once sentenced him to probation after he set fire to a chair during a 1994 appearance on “The Tonight Show.” That same year, during a guest spot on “The Arsenio Hall Show,” Goldthwait launched into an unscripted 10-minute tirade against the program’s Paramount Television producers, who had recently announced they were canceling Hall’s show. During the outburst, Goldthwait spray-painted “Paramount Sucks” on the set’s backdrop and pulled two TV monitors off their stands.

Goldthwait’s love-hate relationship with Hollywood leaves everyone unsure whether he’ll bite or kiss the hand that feeds him.

“Doing a monologue on ‘The Tonight Show’ was probably success on my own terms, but at the time I viewed being on that show as some kind of weird sellout,” said Goldthwait, who is surprisingly soft-spoken during the interview, sounding nothing like the hyperventilating one-step-shy-of-going-over-the-edge character he presents onstage. “In the meantime, I end up doing things that are even more compromising and restrictive, like voice-over work.”

As a voice-over actor, Goldthwait may be best known as Mr. Floppy on the lowbrow WB sitcom “Unhappily Every After.” Mr. Floppy was the stuffed bunny that dispensed cynical advice to Jack Malloy, the show’s loser father.

Goldthwait hardly seems crushed by the cancellation of “Unhappily Ever After,” which recently concluded a five-season run. He said the highlight of his stay with the series was getting to know Cox, who played Malloy’s sexpot teen daughter.

“I can’t imagine an easier job,” he said. “I would spend a day and a half a week on the set. I didn’t have to worry about wardrobe or makeup or even the lines. I would be in this little closet by the stage with the script in my lap, though occasionally I would drop the script [during a show taping], and you would hear cursing coming out of the rabbit!”

Goldthwait seems similarly unfazed by the recent cancellation of his short-lived FX cable TV program, “Bobcat’s Big Ass Show,” a comedy/game show that featured contestants revealing hidden secrets or talents.

*

In recent years, Goldthwait has landed numerous jobs doing voice-over work for animated projects including Disney’s “Hercules” film and TV series. He’s also a frequent guest on “Hollywood Squares,” which airs at 7:30 p.m. on KCBS Channel 2.

Though he says he’s not holding his breath, Goldthwait would like to get financial backing for a feature film script he’s working on called “Teen Jesus.” It’s a comedic look at the teen years of Jesus Christ: He cites “Jesus walking across the pool at the swim meet” as an example of the type of comedy bits in the script.

Eight years ago, Goldthwait wrote, directed and starred in a black comedy called “Shakes the Clown.” Featuring an alcoholic clown lead character, the feature film generated numerous hostile reviews, as well as protests from offended clowns.

“During its peak of its release, it was only on 15 screens [across the country],” he said. “But the press acted like it was being rolled out onto 1,000 screens. It was crazy how angry some of the critics got. But after a while, things were OK. I do run into a lot of people who liked it, and it’s become a cult [favorite].”

“Shakes” has been popular on rock tour buses, he said. R.E.M. even wrote a song called “Binky the Doormat” based on the movie’s villain, a coke-sniffing clown who frames Shakes for murder.

Goldthwait said he’s quite content now to concentrate on his “bread and butter”: stand-up.

His humor is both personal and observational. Of President Clinton’s impeachment acquittal, he jokes, ‘Jack and Bobby Kennedy are in hell right now saying, ‘Dammit, we didn’t have to kill Marilyn!’ ”

Even traveling to countless comedy clubs across the country has gotten to be less of a grind for Goldthwait, thanks to the presence of Cox (who, by the way, said yes to his marriage proposal) and his 12-year-old daughter.

“It’s been much nicer lately,” he said. “Nikki travels with me a lot, and my daughter goes out on the road with me. It’s been really good.”

* Bobcat Goldthwait performs tonight at the Coach House, 33157 Camino Capistrano, San Juan Capistrano. 8 p.m. $25-$27. (949) 496-8927.