SAN DIEGO — Bill Murray made his first-ever Comic-Con appearance on Thursday, charming the throngs of geeks who camped out for the opening day of the confab.

Dressed as his “Rock the Kasbah” character Richie Lantz, Murray spoke coolly, but passionately about everything from Barry Levinson’s new movie, which opens this October, to some of his famous co-stars.

“Is Bruce Willis really a jacka–?” one fan asked. Murray, who first worked with Willis on Wes Anderson’s “Moonrise Kingdom,” defended the actor in his absence.

“He’s a movie star,” Murray said, saying that he and Willis shared a trailer while filming “Rock the Kasbah” in the harsh conditions of Morocco, where temperatures reached up to 116 degrees.

“When you’re a movie star you sometimes have to take matters into your own hands,” he said. “In the name of entertainment and just respecting the crew … there are people who try to take advantage of a group situation and dominate (“producers slime”) and a movie star can step in and say ‘That ain’t gonna happen boss.'”

Murray also spoke about Sofia Coppola’s star-studded Christmas special on Netflix, featuring everyone from George Clooney to Miley Cyrus.

“Miley Cyrus is really f—ing good!” he exclaimed.

Although Thursday marked Murray’s debut at the pop-culture convention, he said he felt right at home among the fanboys, partly thanks to their passion and excitement. “Some of the best parties I’ve ever been to are with nerds,” he said.