Legendary comedian Don Rickles, who died on Thursday at 90, was sarcastically nicknamed “Mr. Warmth” for his razor-sharp wit and biting mock disdain for Hollywood stars, notables and heads of state.

Martin Scorsese, who directed Rickles in the 1995 film Casino, told the Hollywood Reporter:

Don Rickles was a giant, a legend…and I can hear his voice now, skewering me for being so lofty. I had the honor of working with him on my picture Casino. He was a professional. He kept me doubled over with laughter every day on the set – yet he was a complete pro. We became friends over the years and I had the honor of being roasted by him more than once – sometimes when I didn’t expect it. He just started showing up at places and insulting me. Experiencing Don, and tuning into his mind, I witnessed the evolution of his comedy. It was like listening to a great jazz musician wail. Nobody else did what he did. He made comedy into an art form. And like all geniuses, comic or otherwise, he’s irreplaceable. He was much loved. I’m really missing this man.

On social media, Hollywood paid tribute to Rickles:

One of the bravest, funniest, and sweetest guys that ever performed. A dear pal that we will all sorely miss.
Mel Brooks
90 years with Don Rickles weren’t enough. One of the sweetest and most lovely people I had the pleasure of knowing. We miss you already
Jimmy Kimmel
Don Rickles has passed away.
A giant loss.
Billy Crystal
May the legendary Don Rickles rest in peace. He was one of the greats.
Seth MacFarlane
Those were the days, my friend Don Rickles. We thought they’d never end. We loved you so.
Dick Van Dyke
A God died today. Don Rickles, we did not want to ever lose you. Never.
Tom Hanks
I was thrilled to interview/be insulted non-stop by the legendary Don Rickles. I will sorely miss this incredibly funny and lovable man.
Conan O’Brien
Don Rickles you will be horribly missed. But God will be so honored when you call him a Hockey Puck.
Sarah Silverman
Don once begged me for a couple of bucks then told me to twist myself into a pretzel. Ego slayer! Comic Everest! Spank you, Mr Rickles.
Jim Carrey
He was the love of my life . Don Rickles is funnier right now in death than most comics are in life.
Chris Rock
Don Rickles was one the absolute greats. I feel lucky for the times I was ever in his orbit, my thoughts are with his family today.
James Corden
Awwww man Rickles is dead. Rest In Peace buddy.
Danny DeVito
Don Rickles was an absolute legend, my favorite comedian, and also my friend. Rest in peace.
Mark Wahlberg
He never was Politically Correct and he never apologized for it. R.I.P. Don Rickles
Gilbert Gottfried
In lieu of flowers, Don Rickles’ family has requested that people drop their pants and fire a rocket.
Patton Oswalt
A national treasure is gone. Don Rickles’ talent was limitless. To know him was a gift. He kept me laughing during 58-years of friendship.
Larry King

New York Times Obit