Otto Petersen, a ventriloquist who was the flesh-and-blood half of Otto and George, a comedy team renowned for vulgarity so stunning as to make Rabelais look like a church picnic, died on Sunday at his home in Keyport, N.J. He was 53.

Mr. Petersen died in his sleep, his longtime companion, Tricia Conte, said. He had been hospitalized last year for bacterial meningitis; whether the illness played a role in his death is unknown, she said.

With George Dudley, his wooden companion of four decades, Mr. Petersen was a frequent guest on “The Opie & Anthony Show” and “The Howard Stern Show,” both on SiriusXM satellite radio. On television, he was seen on “Late Show With David Letterman” and elsewhere.

Popular with audiences and widely admired by other comics, Mr. Petersen was often described as soft-spoken in private life. But he was no match, he often said, for the strong-willed, forked-tongue George, whose caustic, profanity-laced outbursts rained down on a spate of targets, not least of all Mr. Petersen himself.