Don Rickles had two special gifts: the audacity to make fun of anyone and everyone, often to their faces, and the skill to do it so hilariously that no one really cared he was laying down insult after insult.

Rickles died on Thursday at age 90, but his comedic legacy will never be forgotten. He was best known as an insult comic, blessed with a quick, raunchy wit and an utter lack of shame. Whether you were Frank Sinatra or Ronald Reagan or some random person in his audience, you were a fair target.

In Mr. Warmth, a 2007 documentary about Rickles, a wide range of Hollywood personalities, from Whoopi Goldberg to Clint Eastwood to the late Robin Williams, all comment on how the comedian would be completely bombastic and offensive on topics like race, religion, sex, and gender, but was so talented and funny that even those who would’ve otherwise been upset by Rickles’s material tended to walk away impressed.

You can see one of the comedian’s best displays of this skill in his roast of Frank Sinatra during 1978’s The Dean Martin Celebrity Roast: Frank Sinatra. Rickles clearly couldn’t care less that Sinatra and the Rat Pack were basically Hollywood’s version of the Avengers. He went after each and every one, landing jokes about Bob Hope looking for a war, suggesting that Dean Martin should be slapped to keep him from passing out, and riffing about Ronald Reagan throwing temper tantrums.

“I make fun of blacks, whites, Jews, Italians—” Rickles quips. “Well, Jews. We’re the chosen people, we had a few bum breaks — the Red Sea trick.”

You can trace that same spirit through Rickles’s performance at Reagan’s second inauguration in 1985:

“I make fun of the president, why not?” he says. “I make fun of everyone. That’s America. Charlton Heston, I’m a friend. It’s over. I’ll tell you this. If you were Moses, I was a Mau Mau fighter pilot.”

To younger generations, Rickles is probably best known as the voice of Mr. Potato Head in Pixar’s Toy Story franchise, a role that shows off another side of his humor and his gift as a voice actor:

That Rickles was able to make people laugh by both voicing a grumpy potato and insulting people right to their faces with one irreverent joke after another was a testament to his deft comedic skill, which ran much deeper than the phrase “insult comic” might suggest.