Richard Lewis, the stand-up comedian who parlayed a dark sense of humor into an acting career that included movies and TV, died on Feb. 27 at his home in Los Angeles. He was 76.

Neurotic and self-deprecating, typically dressed all in black, Mr. Lewis paced the stages of comedy clubs, hanging his head, pulling at his shock of black hair, riffing on his struggles in life and love. He called himself “The Prince of Pain.”

Beginning in 1999, he had a regular role on “Curb Your Enthusiasm” as a good friend and golf buddy of Larry David, the show’s star and creator. He played a semi-fictionalized version of himself, a dour personality who made Mr. David’s otherwise prickly self seem like Christopher Robin.

“I owe my career to my mother,” Mr. Lewis told the Washington Post in 2020. A woman with issues, he said, “I should have given her my agent’s commission.”

Jason Zinoman, in an appraisal in The New York Times, wrote of the friendship between Lewis and David, “These cantankerous Brooklyn Jews made harangues seem like hugs.”