Mitch Hedberg, the lackadaisical, longhaired comedian whose surreal routines made him a cult figure on the national comedy circuit, died on Wednesday in Livingston, N.J., said his father, Arnold. He was 37.

The cause was not immediately known, said Michael O'Brien, his publicist. The Pioneer Press of St. Paul, Minn., his hometown, reported that Mr. Hedberg had a heart attack.

A shy, self-styled outsider, Mr. Hedberg carved a career out of casual observations delivered in a mumbling drawl. "I'm against picketing," he would say with a sly smile. "But I don't know how to show it."

Comedy was not a natural choice for Mr. Hedberg, who battled stage fright, and sometimes closed his eyes as he performed. Alcohol and drugs, however, played a large role in his on- and offstage routines. According to a profile in The Los Angeles Times, he was arrested in 2002 for possession of heroin. "I used to do drugs," went one of his most quoted jokes. "I still do drugs. But I used to, too."