Factbox: Six facts about comedian Don Rickles

(Reuters) - Comedian Don Rickles died on Thursday at the age of 90 at his Los Angeles home, his publicist said. Rickles, also an actor and a best-selling author, was nicknamed Mr. Warmth in a facetious reference to his barbed jokes. He died of kidney failure. Following are six facts about Rickles. * Rickles was not always an insult-slinging comedian. He graduated from the American Academy of Dramatic Arts in New York, where his classmates included Jason Robards, Grace Kelly and Anne Bancroft. He had an early undistinguished stage career before gravitating toward comedy work, starting out in strip joints and working his way up to nightclubs, casinos, records, television and movies. * Rickles did not think of himself as an "insult comic." He said his act was all in fun and that his barbs were exaggerations delivered with good humor. "I'm the guy that makes fun of the boss at the Christmas party on Friday night and Monday still has his job," he once said. * Rickles inspired lots of nicknames. Singer Frank Sinatra called the short, bald comedian "Bullethead" while late-night television host Johnny Carson gave him the facetious title "Mr. Warmth" and Milton Berle dubbed him "The Merchant of Venom." * One of Rickles' most notorious put-downs was to call someone a "hockey puck" but he once told an interviewer he was unsure how he came up with the barb. * A lifelong Democrat, Rickles performed as part of Ronald Reagan's second presidential inauguration. He joked that he took the job because he wanted to hang out with Sinatra. * Rickles was a devoted son but in his act referred to his mother, Etta Rickles, as "the Jewish Patton." (Writing by Bill Trott; Editing by Jill Serjeant)