You may know him as Mr. Potato Head from Toy Story; you may know him from his classic appearances on The Tonight Show and Dean Martin celebrity roasts; you may have actually seen him perform in Vegas. But if you watched Spike TV’s One Night Only: An All-Star Comedy Tribute to Don Rickles special, it’s a safe bet you learned a little something more about 88-year-old comedy legend Don Rickles.

Like, why an A-list group of celebs that included David Letterman, Tina Fey, Amy Poehler, Jerry Seinfeld, Robert De Niro, Tracy Morgan, Jon Stewart, and Johnny Depp showed up to give him hugs, kisses, and healthy servings of the insults he’s been delivering throughout his more than 50-year career.

Watch Jerry Seinfeld pay tribute to Don Rickles right here:

Here, a primer on how the king of insults earned himself an evening of ribbing (and, of course, a standing ovation):

1. As the most successful insult comic of all time, Rickles gets away with saying things no one else can. In the 2007 Emmy-winning documentary Mr. Warmth: The Don Rickles Project, Chris Rock offers a theory on how Rickles has always gotten laughs with jokes that would be considered extremely politically incorrect coming from any other comedian. “Some guys just have that thing. It’s like, being funny is like being a pretty girl. You get away with a lot of s--t. It’s like he’s got big t-ts.”

2. His group of famous cohorts rivals Frank Sinatra’s Rat Pack for coolness. Sinatra and the Rat Pack, in fact, were among Rickles’s closest pals, and he writes in his 2008 autobiography Rickles’ Book: A Memoir that he was regularly invited to join Sinatra, Dean Martin, Sammy Davis Jr., and the rest of the Pack for their 5 p.m. daily steam room sessions at the Sands in Las Vegas.

Sinatra, who nicknamed Rickles “Bullethead,” was introduced to him when Rickles’s mother befriended Sinatra’s mother in Florida and asked Mrs. Sinatra to encourage her son to help boost Rickles’s career. Rickles won Sinatra over when, the first time Sinatra went to see him perform at a Florida nightclub, he insulted him. “Hey Frank, make yourself at home!” Rickles said. “Hit somebody.”

Sinatra would later help Rickles secure what he has called the highlight of his career: performing at Ronald Reagan’s 1985 inauguration. Sinatra had refused to perform himself unless Rickles was also on the roster.

Among Rickles’s other celeb friends: Johnny Carson, who gave Rickles the sarcastic nickname “Mr. Warmth”; Larry King, who hosted a 1-to-5 a.m. radio talk show from a houseboat in Miami Beach in the 1950s and regularly invited Rickles on the air to insult listeners who called in; and Bob Newhart, Rickles’s best friend.

3. Rickles and his wife Barbara and Newhart and his wife Ginnie have traveled throughout the world together after becoming friends in Las Vegas more than 40 years ago. And though Rickles and Newhart’s comedy styles are completely different — Rickles calls his friend “Charlie Everybody” because of his laid-back, nice-guy personality — they have teamed up to wreak comic havoc.

[Related: Bob Newhart on 'The Bob Newhart Show' and 'The Big Bang Theory']

In 1976, Newhart was a guest host on The Tonight Show, with pal Rickles as his guest. During the show, Rickles was goofing around with a cigarette box on the host's desk and broke it. When Johnny Carson returned from vacation and found his broken cigarette box, he was “outraged,” and decided to confront Rickles... who was in the studio next door filming an episode of his two-season NBC sitcom C.P.O. Sharkey.

Carson barged onto the C.P.O. set, with camera in tow, and called his friend a “big dummy” and teased him for several minutes before returning to his own set. A clip of the classic confrontation, seen below, was also featured in Spike TV’s One Night Only.

4. Though Rickles is best known as a comedian, he trained as a serious actor at the American Academy of Dramatic Arts in New York, one of the oldest acting schools in the world. His classmates includes Jason Robards, Tom Poston, Don Murray, Oscar winner Anne Bancroft, and Grace Kelly. Among his dramatic roles, he co-starred with Clint Eastwood in Kelly’s Heroes, with Robert De Niro in Martin Scorsese’s Casino, and with Clark Gable and Burt Lancaster in Run Silent, Run Deep.

5. Rickles also played characters named Jack Fanny, Big Drop, Big Drag, and Big Bang the Martian in four of the Annette Funicello/Frankie Avalon beach movies of the 1960s. Rickles’s agent, Jack Gilardi, was married to Funicello at the time. Years later, when Rickles was seated next to Barbara Bush during a White House state dinner, he says she ribbed him about his roles in the beach flicks. “Were things so bad that you had to do Bikini Beach and Beach Blanket Bingo?” the First Lady asked.

6. And he has guest starred on dozens of TV shows, including Gilligan’s Island, The Twilight Zone, The Addams Family, The Munsters, The Dick Van Dyke Show, The Beverly Hillbillies, The Andy Griffith Show, Gomer Pyle USMC, I Spy, I Dream of Jeannie, Get Smart, The Lucy Show, Sanford and Son, Newhart, Gimme a Break, Archie Bunker’s Place, Hunter, Murphy Brown, The Unit, and Hot in Cleveland.

7. Rickles writes in Rickles’ Book that he was skeptical about doing the first Toy Story movie, the project that introduced him to a new generation of comedy fans. But when Pixar honcho John Lasseter explained the Toy Story version of Mr. Potato Head would be a “sarcastic wise guy,” the comedian signed on. “I became a hero to a whole generation of children,” Rickles writes. “Even today, my own grandchildren aren’t impressed that I’ve played Vegas for fifty years, but they are impressed that their Pop-Pop is Mr. Potato Head.”

8. In addition to being on the business end of wisecracks from a legendary talk show host and a First Lady — and, during the Spike TV special from Tina Fey, who joked she saw the aged Rickles and thought “that was somebody’s purse” — Rickles is also humble enough to appreciate a quick one-liner from a stranger on the street. In his memoir, he recalls walking down the street in New York with actor pal Joseph Bologna. A homeless man approached them and asked for money. Rickles gave him a $5 bill and said, “Go buy yourself a ranch.” The homeless man turned back and said, “Hey, mister, now I need cattle.”

9. On-stage persona aside, the consensus among Rickles’s friends, and the celebrities who take the stage to roast him during the Spike TV special, is that he is genuinely a very nice man. “We enjoy each other, we make each other laugh," Bob Newhart tells Yahoo TV about his relationship with Rickles. "We have the same values, the wives get along, and our kids grew up together... I wish everybody had the kind of friendship we have.”

One Night Only: An All-Star Comedy Tribute to Don Rickles airs Wednesday at 9 p.m. on Spike TV.