He always had them laughing their heads off.

The hero cop who nabbed the killer behind the legendary 1983 New York Post headline “Headless body in topless bar” died Friday after a long, fittingly colorful life.

Retired New York City Transit Police Detective Frederick “Freddy” Mack, 79, passed away while in hospice care, his daughter Debbie Comstock told The Post on Sunday.

“He was a man full of character,” Comstock, 58, said. “He always had stories and jokes to tell. He was loved by many.”

Perhaps Mack’s biggest story of all unfolded in April 1983, after 25-year-old lowlife Charles Dingle spent a night drinking in Herbie’s Bar in Jamaica, Queens.

A thoroughly sauced Dingle got into an argument with the topless watering hole’s owner, Herbie Cummings, and shot the barkeep in the head, killing him.

Rather than flee the horror, Dingle decided to plumb deeper depths of depravity, tying up four women who were in the bar and eventually raping one of them.

After discovering another woman there was an undertaker, Dingle ordered her to cut off Cummings’ head and put it in a box.

Dingle held two of the women hostage, drunkenly driving them to Manhattan in a stolen gypsy cab until he fell asleep. The women ran off to a nearby subway station and hopped a train to Columbus Circle, where Mack was stationed as a transit detective.

An initially skeptical Mack went to investigate the frantic women’s story, coming face-to-face with the ding-a-ling Dingle, who was just waking up and reaching for his gun.

Mack, who had left his own weapon behind at the station in the rush, didn’t hesitate to take action, said his friend Mike Fanning, a retired NYPD detective.

“That’s when he confronted the suspect, wrestled him, took [Dingle’s] gun and then looked in the backseat and saw the head,” Fanning said.

Comstock said she remembers her raconteur father coming home afterward and telling the stranger-than-fiction story at the dinner table. She said he found the bar owner’s severed head in what appeared to be a bakery box.

“That was everyday dinner conversation for us,” she added with a laugh.

The capture of Dingle and the salacious strip-club decapitation inspired The Post’s most iconic front-page headline, “Headless body in topless bar.”

For Mack’s family and friends, his role in New York City history wasn’t actually a surprise.

The Marine Corps veteran-turned-transit detective had an eventful life before and after his brush with Dingle.

Comstock said her dad had also worked as a bat boy for the Dodgers and counted the team’s former manager Tommy Lasorda as a friend — a pairing that Fanning also fondly recalled.

“When [Mack] retired, he did some private investigation work and knew several celebrities,” Fanning said. “Tommy Lasorda always came by to visit him and sign baseballs for the cops.

“Freddie was an excellent investigator and an even better friend. He worked in Transit Major Case working on all the big cases, but he always had time for young cops. He was a dogged detective and a great teacher, very helpful. He was also very funny.”

Mack retired in 1988 after he was struck by a taxi, Comstock said. He moved to Florida, where he worked with a local jail and volunteered with an evangelist group connected with country music legend Charlie Daniels, his daughter said.

After the Sept. 11, 2001, terror attacks, Mack volunteered at Ground Zero, Patch reported.

He also recounted his role in capturing Dingle for the Jerry Springer-hosted show “Tabloid” in 2014.

Dingle was sentenced to 25 years to life for his rampage. He tried to deny that he committed the heinous crimes and was refused parole several times before dying behind bars in 2012, prison records show.

Fanning said Mack didn’t volunteer telling the story but wouldn’t hesitate after prodding to rehash the whole bloody affair.

The story became so intertwined with Mack that his fellow cops gave him cake in the shape of a head at his retirement party, Fanning said.

“Later that night when his wife went into the refrigerator to get something, she saw the head and screamed, waking Fred up,” Fanning said.

Comstock laughed when remembering the morbid severed-head cake.

“That is true,” she said. “You would never know what you’d walk into.”