On July 22, 1979, a furry pinstriped fellow with a big belly, spinning baseball hat and giant ginger mustache strode out into Yankee Stadium.

Dandy, the Yankees’ first and only mascot, had made his world debut. Inside the costume was Rick Ford, a 22-year-old Ithaca College grad from Greenwich, Connecticut, who had been practicing for his big moment for months, ready to wow the crowd and do for the East Coast what the San Diego Chicken had done for the West.

It didn’t go exactly as planned.

“They originally wanted me taken out on the field in a truck and then I’d pop out of the roof,” remembers Ford, now 62. “[Team organist] Eddie Layton had composed a song just for Dandy. It was going to be great.”

Instead, Ford emerged from the stadium’s weight room and was led by a PR person directly to the stadium’s upper deck.

“I never got an introduction,” Ford said. “Nobody had any idea what I was or what I was doing there. They just looked at me like, ‘What the hell is this thing?'”

Dandy’s inauspicious beginning led to a short-lived tenure that the Yankees have seemingly tried to scrub from the record books. A 1998 story on baseball mascots from The New York Times was unable to find any Yankee representatives willing to acknowledge Dandy ever existed. Yankees owner George Steinbrenner insisted he had “no recollection” of Dandy.

Even the Times’ own reporting couldn’t verify much, guessing (incorrectly) that Dandy roamed Yankee Stadium somewhere between 1982 and 1985. His life span was actually between 1979 and 1981.

Yankees team spokesman Michael Margolis declined to comment on Dandy for The Post, saying only that “there’s just no one left from that era that could speak to that experience.”

Designer Bonnie Erickson, who co-created Dandy — along with the far more successful baseball mascot the Phillie Phanatic — isn’t surprised the Bronx Bombers want to erase their failed experiment.

“They always struck me as a team that’s very proud of their legacy,” she said. “Why would they want to admit that they tried something that didn’t work?”

The exact origins of Dandy are still unclear.

AJ Mass, author of “Yes, It’s Hot in Here: Adventures in the Weird, Woolly World of Sports Mascots,” suspects that the huge success of the Phillie Phanatic, who debuted in 1978, fueled Steinbrenner’s decision. “George probably didn’t like the idea of Philadelphia one-upping him,” he said.

At the time, Erickson and her partner, Wayde Harrison, had a puppet-design workshop on Fifth Avenue and 17th Street and say they were approached by Yankees executives to create a mascot.

The pair’s track record inspired confidence. Erickson worked with Jim Henson on shows like “Sesame Street” and “The Muppet Show,” designing classic characters like Miss Piggy and the elderly hecklers Statler and Waldorf.

“[The Yankees] didn’t really give us any information about what they wanted,” Erickson said. “We knew they were interested in increasing family attendance, and they thought this was the way to do it. They left the design up to me.”

The designers met with Steinbrenner only once, in his office to review their sketches. It nearly ended in disaster when the notoriously prickly owner took issue with the shade of blue on Dandy’s outfit.

“I did a design that I called a dyed-in-the-wool Yankee,” said Erickson. “The pinstripes were more of a royal blue. Steinbrenner wanted it to be Yankee blue, and we knocked heads about that.”

Although the executives standing in the background were horrified that anyone would be so combative with The Boss, Erickson soon convinced Steinbrenner that royal blue would read better on muppet fur. The Yankees agreed to rent the costume for $30,000 for a three-year trial run.

Ford was still an acting student in college when his uncle introduced him to Erickson, who asked if he’d be interested in playing Dandy. He eagerly came to her workshop to don the costume and “dance to some music and tumble around to show what I could do with it.”

His final tryout (with Steinbrenner watching from the stands) was on a non-game day in Yankee Stadium in June 1979. Ford remembers that two players, Reggie Jackson and Goose Gossage, were also on the field — and they both burst into laughter when they first set eyes on him.

“Gossage turned to Jackson and says, ‘Boy, wait till Thurman gets a load of this guy. He looks just like him,’ ” Ford remembers.

Dandy did slightly resemble Yankees catcher Thurman Munson, or at least his mutual style of facial hair.

But Erickson insists Munson wasn’t the inspiration behind Dandy. “I didn’t even know who he was,” she said of the team’s then-captain. “I looked at old photos of the team from the early 1900s, and many of the players in those days had big, bushy mustaches,” she said.

But nobody looked at Dandy and saw a loving historical homage. They saw Munson. It was the first bad omen of what was to come.

Just weeks before Dandy’s world premiere, during an early July 1979 game in Seattle, Yankees outfielder Lou Piniella became enraged by the San Diego Chicken, who was pretending to put a hex on the pitcher’s ball. He got so upset that he threw his mitt at the Chicken and told reporters later that the mascot “doesn’t belong on the field. Let him do his routine somewhere else. Don’t let him clown around out there where the players are trying to make a living. It’s distracting.”

Steinbrenner publicly echoed Piniella’s remarks later, essentially demanding that mascots be banned from professional baseball.

“It was all over the news,” said Harrison. “That’s not what we wanted to see as we were getting ready to unveil our own mascot. We were like, ‘Oh, my God, we’re screwed!’ ”

Ford still got the job as Dandy and his debut was set for a matchup with the Seattle Mariners, but with decidedly less fanfare than its creators had originally expected. The new plan, Ford was told, was to do a slow rollout, so as not to contradict Steinbrenner’s comments about mascot interference.

“I could go anywhere in the stands, just nowhere near the dugout or the field,” Ford said.

Beyond fame, there was little compensation in the role. Ford made $40 for every home game, which translated to a yearly salary of $3,240 (or just over $11,000 in 2019 dollars). It was a far cry from the $50,000 salary (a six-figure sum today) the San Diego Chicken was pulling in that same year.

“It was embarrassing because everybody thought I was making a fortune,” Ford said. “Steinbrenner was famous for paying all his players a hefty salary, so why would it be any different for his mascot?”

It didn’t help that Yankees brass gave Ford no guidelines. “I was winging it,” he said. “I had no idea what I was doing. Nobody at the Yankees gave me any direction. I was just making it up as I went along.”

Meanwhile, Yankees fans had little or no idea who he was. Though the moniker “Dandy” was the winning entry in a “Name the Mascot” contest for fans — possibly as an allusion to “Yankee Doodle Dandy” — “nobody called me Dandy,” Ford said. “Nobody knew the name. They all called me the Chicken. They were like, ‘Hey, there’s the Yankee Chicken!’ Or sometimes just ‘Mr. Mascot.’ ”

Ford was contractually required to work with a bodyguard, because fans could occasionally get rough. “They gave me two bodyguards when the Red Sox came to town,” he said.

He remembers one incident where a man approached him, asking Dandy to sign a note for his son. “I can’t even move my fingers in this outfit, so I’m shaking my head no,” Ford remembers. “And my bodyguard is like, ‘Sorry, he can’t do that.’ But the guy keeps asking, ‘Oh come on, Mr. Mascot, it’s his birthday!’ ”

Ford finally managed to scrawl a large X on some paper. The father looked at it and exclaimed, “What the f–k is this?” Then he crumbled up the paper, threw it at Dandy and shouted, “F–k you!”

Even so, it’s one of Ford’s favorite Dandy memories. “I felt like a real New Yorker,” he said.

Weeks into his new gig, Ford started to feel more accepted. He remembers one game where Munson approached him during a mid-inning water break.

“He winked at me and said, ‘You’re doing a good job, kid,’ ” Ford said. “I’ll never forget that for the rest of my life.”

But then tragedy struck. In early August, the 32-year-old Munson died when he lost control of the aircraft he was piloting and crashed near the Akron-Canton Airport in Ohio. It was a devastating loss for the Yankees and the worst possible news for Ford.

“I showed up for work as usual and they said no, you’re not going out there dressed like Munson,” Ford said. “I knew I was in trouble.”

Munson’s death and Steinbrenner’s anti-mascot policy certainly doomed Dandy, but there are other reasons for the mascot’s early demise.

“I don’t think the Yankees of the ’70s — the Bronx Zoo — was the right organization to have a mascot,” said Mass. “They were gruff, they were brawlers. They didn’t need a mascot. They were their own sideshow.”

And the brawling could sometimes get real. At a 1980 Citibank pep rally at Madison Square Garden, Ford had to bring his own bodyguard — a friend he paid with subway fare — and he was still attacked by the thoroughly soused audience.

“I fell off the stage, and they just lunged at me,” Ford said. “I heard somebody scream, ‘Unzip his head! Unzip his head!’ I was pretty scared.”

Rattled by the experience, Ford said he declined to return the Dandy costume until the Yankees paid him the extra fee and travel expenses he’d been promised for the Citibank show. The Yankees eventually paid up and then stopped calling.

“Nobody really explained why,” Ford said. “They were just done with me.”

He was replaced by a New York actor named Darren Edwards, and Dandy remained the league’s least visible mascot for two more seasons until Erickson and Harrison — rather than the Yankees — pulled the plug.

“They wanted to re-sign,” said Harrison, who still co-owns the Dandy copyright with Erickson. “But they weren’t willing to pay for a security person anymore, and that wasn’t a negotiable point with us.”

Why would they want to admit that they tried something that didn’t work?

Dandy’s creators, who now run their operation out of Brooklyn, have a healthy sense of humor about their short-lived Yankees mascot, born 40 years ago this summer.

“He could have been a star,” laughs Erickson, who went on to design 16 more mascots for teams from the Orlando Magic to the Montreal Expos.

Other than early sketches, she and Harrison expunged all traces of Dandy, shredding the costume before disposing of it in a dumpster in 2000.

“As with most character costumes, if you’re not going to use it and you don’t want to store it, you have to destroy it so it doesn’t show up on the street or in somebody’s auction house,” she said.

But there is one happy ending to Dandy’s story.

Shortly after Ford signed on as the mascot in 1979, he had a blind date with a woman named Page whom he calls “way out of my league.” Before they parted ways, he gave her his business card, which included a tiny sketch of Dandy.

Two decades later, Ford was still living with his parents in Connecticut and still a struggling actor, when he got a letter from Page. She’d stumbled upon his card in a box of old mementos, and the drawing of Dandy made her laugh. “Do you remember me?” she wrote.

He did, and they soon started dating. A year later, they were married. “Eighteen years and we’re still madly in love,” said Ford, whose last acting gig was a murder-mystery musical in New Jersey.

“Dandy never made me rich or famous like I’d hoped, but he helped me find my soul mate. So I still consider myself a pretty lucky guy.”