NEW YORK, NY—Time clearly doesn’t heal all wounds.

When it comes to the relationship between TBS late-night star Conan O’Brien and his corporate colleague Jeff Zucker, all is not forgiven.

O’Brien, entertaining the crowd at Wednesday’s WarnerMedia upfront at the Theater at Madison Square Garden with a blood-drawing standup routine that was the comedy equivalent of barbed wire, took the opportunity to skewer the company’s new chairman of news and sports. Zucker played the decisive role in taking The Tonight Show away from O’Brien, and giving it back to Jay Leno, when Zucker was chief executive and chairman of NBCUniversal a decade ago.

During a riff on a supposed made-for-television movie about last year’s acquisition of Time Warner by AT&T, O’Brien showed lookalike photos of various actors who’d been cast to play different AT&T and Time Warner executives.

Among O’Brien’s casting choices that were flashed on a big screen behind him: James Taylor for WarnerMedia CEO John Stanke (“and that’s James Taylor being told who John Stanke is”); Muppet Guy Smiley for AT&T chief Randall Stephenson; and “the guy on the box for Just for Men Ginger” for WarnerMedia entertainment chairman Bob Greenblatt.

And the diminutive, bullet-headed Zucker, O’Brien said, will be played  by Mini-Me (i.e., the late two-foot-eight-inch-tall actor Verne Troyer)—which, in contrast  to audience chuckles for the other pairings, got a loud and pained “Ooooh” from the crowd.

“We go back, he and I,” O’Brien explained, to rising laughter, as Zucker, occupying a prime seat near the stage, made the best of it. He did not respond to The Daily Beast’s request for comment.

Zucker was not O’Brien’s only target. He mercilessly mocked the buttoned-down Stanke, who opened the proceedings with a restrained, droning, introduction punctuated by corporate-speak—which featured, among other elements, the history of the invention of the telephone.

“I was worried you guys would be a little tight this morning,” O’Brien began. “But then John Stanke came out and RIPPED INTO A FRENZY!… HE INVENTED THE TELEPHONE APPARENTLY!”

O’Brien went on: “I just met John Stanke backstage… We had a very nice and warm moment. I said ‘hello’ and he said ‘I thought we got rid of you.’…

“Welcome to the upfront, ladies and gentleman! It’s the Oscars for people who love PowerPoints!”

Noting the “big, big changes” post-merger, O’Brien said that last year’s event was called the Turner Upfront. “Now it’s called the WarnerMedia Upfront. I look forward to seeing you next year when it we be called the P.F. Chang’s/WarnerMedia Upfront!”

O’Brien continued: “This is the first upfront since Time Warner was bought by AT&T. And because this is AT&T, after  the show there will be a terrible reception. Because it’s AT&T, the after-party has only two bars.”

Citing the “hotly anticipated” arrival of WarnerMedia’s new streaming service, O’Brien said: “I like their slogan: Let WarnerMedia be your seventh streaming service!”