WATCH: Paul Rudd Crashes Conan for One Final Mac and Me Prank

Paul Rudd crashed Conan O’Brien’s TBS talk show on Monday to bring an end to one of the longest-running gags in late-night history.

Rudd unexpectedly popped up during the final week of Conan as O’Brien interviewed Saturday Night Live alum Bill Hader, who had been discussing a failed SNL sketch involving Rudd which never aired.

Rudd then claimed to have footage from the dress rehearsal, but when the clip rolled, it was actually a bizarre snippet from the 1988 E.T.-ripoff Mac and Me.

In the clip, a boy in a wheelchair rolls down a hill before falling off a cliff and landing into the water below, as a small bug-eyed alien looks on.

Rudd first debuted the bit in 2004 when he showed the clip from Mac and Me while proclaiming to have a sneak peek at the highly-anticipated Friends finale. He’s recycled the bit for nearly every of one of his appearances on O’Brien’s late-night shows – playing the bizarre scene instead of one from whichever project he was plugging.

“It’s been like 25 years of you coming on the show, and you would always say, ‘I’ve got a clip,’” said O’Brien, “and every time for years I was convinced I would see the real clip, because you’re such a genuinely nice person. And you would say, ‘This movie is really important to me’ and ‘I put my own money into this, and I really care about this,’ and then you’d pull that shit every time.”

Rudd told the host he “never really imagined” the bit would last for nearly two decades.

“It’s absolutely stunning,” O’Brien said. “It’s this crazy performance art that lasts forever.”

Rudd explained, “I just remember thinking the very first time that it’s so artificial to come on and sell your wares and show a clip from your movie. We’ve never talked about this really, but I thought, ‘What if I show a clip from this movie I saw a long time ago that is just really strange?’”

The final episode of Conan airs Thursday, ending O’Brien’s run as the longest-tenured host in late-night history. He’ll next host a weekly variety series for HBO Max.

Watch the clip above, via YouTube.