One of the hooligans who allegedly pelted NYPD cops with snowballs in a rowdy free-for-all at Washington Square Park has been unmasked — as a 27-year-old wannabe YouTube star who was busted during a subway “prank” just weeks ago, police and sources said.

Gusmane Coulibaly was cuffed on Thursday in connection to the Monday afternoon mayhem that sent two uniformed cops to the hospital — and that Mayor Zohran Mamdani had brushed off as kids goofing off.

Police said Coulibaly — who reportedly fancies himself a social media personality and posts under the name “Diaperman” — was charged with obstruction of governmental administration and harassment and was awaiting arraignment Thursday evening.

It wasn’t his first run-in with the law.

He was arrested and charged with attempted robbery at a Bronx subway station on Feb. 6, cops and sources said.

Coulibaly told cops the whole thing was a prank — but the 45-year-old victim didn’t think the boneheaded prank was funny.

YouTube video of that incident showed a man purported to be Coulibaly telling a stranger in the subway that he owes him money.

“When you gonna pay up the money?” video of the interaction shows.

The other man insists it’s a case of mistaken identity, but the supposed caper keeps going.

“Whachu mean you don’t know me? What’s funny?” the YouTuber says, pursuing the other man even as he walks away and claims he’s a cop to try to get the creep to back down.

“If I get mad I’m gonna have to run your pockets,” the “prankster” says, before two plainclothes cops step in and cuff him.

The victim told cops he feared for his safety, sources told The Post.

Coulibaly pleaded not guilty to charges of attempted robbery, attempted petit larceny and harassment and was released on his own recognizance by Judge Tara Collins. He is due back in Bronx court for that case on March 15.

The NYPD Police Benevolent Association president applauded his latest arrest, and took a swipe at Mamdani for brushing off the snowball incident.

“A 27-year-old is not a ‘kid,’ @NYCMayor,” the union posted on X.

“This individual is an adult with a recent attempted robbery arrest, and your message was that it’s OK for him to assault police officers for doing their job. This arrest sends a different message. We’re grateful to all who have worked so hard on this case. There is more work to be done to hold accountable all who participated in this shameful attack.”

But even news of the earlier bust wasn’t enough to change Mamdani’s mind.

“As the mayor has said, police officers deserve to be treated with respect,” mayoral rep Dora Pekec said. “The videos he saw showed a snowball fight that got out of hand. He does not believe this situation rises to the level of criminal charges.”

Coulibaly was one of four suspects pictured in surveillance photos released by the NYPD a day after video of the “snow”-commotion went viral on social media. 

The three others remain at large, police said.

Mamdani also came under fire from the NYPD Sergeants Benevolent Association, which took issue with the lefty mayor’s comments.

“The mayor of New York City has now twice attempted to put his thumb on the scales of justice when police officers are either physically attacked or when their lives are threatened by an individual wielding a knife at them,” union president Vincent Vallelong said in a statement. 

Earlier this month, Mamdani urged Queens prosecutors not to pursue charges against Jabez Chakraborty, a 22-year-old mentally ill man who was wounded by police when he charged at cops with a knife.

“The fact that the mayor has now called for no criminal charges against this assailant has sent a very dangerous tone that the lives of NYC police officers don’t matter,” Vallelong said.  

“We will hold him personally responsible for any further attacks on the NYPD as a result of this reckless and incomprehensible message to violent offenders,” he added. 

Police Commissioner Jessica Tisch previously described the icy incident in the Greenwich Village park as “criminal” and “disgraceful.”

Mamdani said on Tuesday that he had “seen the videos” but downplayed it as just “kids throwing snowballs.”

“I’ve seen the videos of kids throwing snowballs at NYPD officers in Washington Square Park,” he posted on X.

“Officers, like all city workers, have been out in a historic blizzard, keeping New Yorkers safe and cars moving. Treat them with respect. If anyone’s catching a snowball, it’s me.”

Hizzoner then doubled down during a later news conference, insisting the culprits were “kids,” despite footage appearing to show adults.

“I can just tell you from the video I saw, it looked like kids in a snowball fight,” he said.

“I’ve said time and time again that I, having seen these videos, to me it was a snowball fight that got out of hand and it should be treated accordingly,” the mayor insisted.

Tisch told The Post Wednesday, after a meeting with Mamdani administration officials, that she had spoken with the mayor about the snowy skirmish, and that “the investigation is ongoing.” 

She reiterated her no-nonsense stance on the snowballers – or anyone who puts cops in harm’s way. 

“I’ll say, as to anyone looking to do harm to the police, my message is very clear: I am a protective Jewish mother. Don’t mess with my cops,” she said.

In a Tuesday statement, Sergeants Benevolent Association President Vincent Vallelong joined the chorus of voices condemning the rogue winter warriors – and elected officials including the mayor who “were so silent after this incident occurred.”

“When individuals choose to turn a park into a launching ground for attacks on police, they cross a clear line,” he wrote. “Today it is snowballs. Tomorrow it could be rocks, bottles, or worse.”

But many New Yorkers and others believed the cops’ and their boosters’ reactions were a bit overheated and oversensitive.

“Today it is snowballs. Tomorrow it could be anvils, a piano that falls on your head and makes your teeth turn into its keys, a photorealistic tunnel and roadway painted on a brick wall, or worse,” one X user mockingly responded to the sergeants’ union.

“The Russian people were more stoic about Stalingrad during the Nazi siege than the NYPD is about a snowball fight,” Jeet Heer, a writer with The Nation, a prominent lefty magazine, posted on X.