But there’s one instance of intimidation, not previously reported, that stands out in its overreaching pettiness.

Fortune has learned that last July Donald Trump’s “pit bull” lawyer allegedly threatened to have a then 20-year-old English major and his colleagues expelled from Harvard if they didn’t deep-six an elaborate Lampoon prank that had embarrassed his boss.

The prank itself was reported at the time. In a nutshell, the humor magazine’s staffers pretended to be editors of their more serious campus rival publication, the Harvard Crimson, and then persuaded the developer that the newspaper was endorsing him for the Presidency.

Trump hosted them at his Trump Tower offices on Fifth Avenue in New York last July, and posed for a group photograph in which everyone gave him the thumb’s up. He sat in a large wooden armchair, known as the Crimson‘s president’s chair, which the Lampoon staffers had filched from the newspaper’s offices and transported there for the purpose.

Later, when the prank was reported in early August in papers like the Boston Globe, Trump’s spokesperson lashed out at the students as “liars and fraudsters.”

Still, Trump gave the impression that he was taking it all in stride. “Frankly it was a waste of only a few minutes,” read the official statement from his spokesperson. “Mr. Trump attended the great Wharton School of Finance, a school that has more important things to do.”

But not so important, it turns out, that a high-ranking Trump official didn’t first try to coerce the students into destroying their photos and aborting the prank by threatening to otherwise get them all expelled, according to the student who acted as the Lampoon’s liaison with The Trump Organization. (His account to Fortune is corroborated by a Lampoon attorney whom he consulted at the time.)

The official who contacted the student is Michael D. Cohen, 49, who is an executive vice president at The Trump Organization, the main holding company for Trump’s business interests, and special counsel to Trump.

Cohen is known as Trump’s “pit bull,” according to an ABC News story that ran in 2011, when Trump was contemplating an earlier bid at the Presidency. Cohen explained to ABC then, “If somebody does something Mr. Trump doesn’t like, I do everything in my power to resolve it to Mr. Trump’s benefit. If you do something wrong, I’m going to come at you, grab you by the neck and I’m not going to let go until I’m finished.”

According to the Lampoon student, who was then about to enter his junior year, Cohen told him he and his colleagues had committed “fraud,” had wasted Trump’s “time and resources,” and had entered Trump Tower “under false pretenses.”

“I’ll make things very difficult for you,” the student remembers Cohen telling him. “This is something you’ll be dealing with for many years if you keep pursuing it.” Fortune agreed to withhold the student’s name because of his youth.

“I have no interest in commenting on this,” Cohen told me in a brief interview. “This is a ridiculous story. I don’t even know who you got this from.”

When told that I got it from the student he spoke to, he asked to go off the record. When I said no, he declined comment, but then emailed this statement:

“I deny any of the allegations contained in your [email],” which included the threat to have students expelled if they wouldn’t destroy the photos and all the other quotations attributed to Cohen by the student that are reported in this article. “I informed the prankster student that the rightful owner of the stolen Harvard chair had contacted me and wanted it returned immediately. I advised the prankster that if they didn’t return it, I would contact the administration and let them know who had it.” (The temporary misappropriation of the Crimson president’s chair is a longstanding tradition that goes back many decades. It was returned shortly after the students’ visit to Trump Tower. Disclosure: Almost 40 years ago, I was on the Lampoon.)

Here, for the first time, is the inside story of how the whole thing played out.

On June 15, 2015, Trump announced that he was running for President. The Lampoon staffers decided to act fast, assuming that Trump was “at the height of his publicity stream,” as the student liaison explained to me, because the developer’s candidacy “would be gone in a few weeks,” and the magazine would “never have another time.”

The prank would be double-barreled, with both Trump and the Crimson serving as the dual butts of the joke. They’d post online a parody Crimson article endorsing Trump and then get Trump himself—an inveterate tweeter—to distribute it on social media. The preposterousness of the historically left-wing, Upton Sinclair-inspired Crimson editors endorsing Donald Trump for President would be part of the joke.

Scrupulously adhering to hoary tradition, the Lampoon editors purloined the president’s chair from the Crimson headquarters for use during the prank. (Reciprocally, Crimson staffers periodically misappropriate a metal statuette of the Lampoon mascot, an ibis—an awkward wading bird—from the roof of the Lampoon building, known as the Castle.)

The editors then schlepped the chair all the way to Trump Tower, and let Trump sit in it for the photo. Afterward they drew up a lengthy endorsement in language they judged suitably turgid and nonsensical.

“Donald J. Trump is known as a celebrity above all,” it began, “and although some voters see his celebrity as an indication of style over substance, we would argue that this style is the very substance that elevates his candidacy above the rest of the GOP field.”

The endorsement also cited Trump’s proven track-record of job-creation. “For instance,” the students wrote, “his work at The Celebrity Apprentice has allowed him to reach out to celebrities who have been inactive or troubled and help them to redefine their careers through business education and brand building.”

Apparently one of Trump’s staffers had some questions about this write-up, and contacted the Crimson to inquire about it. This time, however, he phoned the Crimson‘s listed phone number, instead of going through the designated student liaison. He reached the Crimson‘s actual president, who then informed him that no endorsement was, in fact, forthcoming, according to the Boston Globe.

Trump’s special counsel Cohen then called the 20-year-old Lampoon officer and spoke to him for about an hour, according to the latter.

“‘We’re going to have a huge problem unless we figure this out right now,'” the student remembers him saying. He took no notes at the time, but recalls Cohen’s diction as being “very ad hominem.”

“He said, ‘I could get on a plane and be there tomorrow, talking to the administration,'” the student continues. “He said . . . he would have us expelled.”

“I didn’t want to get the Lampoon in trouble,” continues the student, who has since switched majors from English to visual and environmental studies. “I was trying to calm him down. I was hoping not to enrage them any further.”

Cohen demanded a copy of the student’s driver’s license and student ID, which he provided. Cohen then demanded, in addition, copies of the IDs of the two Lampoon students who had had cameras and had taken photos at the meeting with Trump, so that he could make sure the photos were destroyed, according to the student.

The student provided Fortune with a screen shot of a text message exchange in which Cohen told him, “I am still waiting for the two IDs. If I don’t receive them, as we discussed, I will be in Boston tomorrow at your school. Please don’t force me to do this.”

(In an email to Fortune, Cohen contends that the two IDs he was referring to in his text were those of “the pranksters who set up the meeting and were in possession of the stolen chair.”)

At that point the student contacted a Lampoon lawyer, Tyler Chapman of Todd & Weld in Boston, who confirms that the student described Cohen’s threats then the same way he does now. “Cohen was not concerned about the chair,” Chapman writes in an email. “He was concerned about stopping the Lampoon’s publication of its prank endorsement of Trump.”

The student then texted Cohen to address all further communications to Chapman, and the threats stopped, he says. The student never heard anything from the college administration.

In late July the Lampoon briefly posted the mock Crimson endorsement and photo on a web site with a URL one letter removed from the Crimson’s actual URL.

The Crimson broke the story of the prank, which was then picked up by the Globe, The Hill, the Washington Post, and others.

But the telling lengths to which The Trump Organization went to try to suppress the prank are only emerging now.

It takes a big man to threaten a 20-year-old college kid.