Adam McKay’s cosmic end-times satire “Don’t Look Up” quickly became the most-viewed original movie on Netflix over the holiday weekend. Endless social media debates over the movie’s quality or scientific accuracy — it’s about a comet on a planet-annihilating collision course toward Earth — aside, viewers who stayed for the comedy’s mid- and post-credits scenes were in for some wild surprises. According to director McKay in a new interview with Variety, the film’s final moments were actually wrought out of the actors’ improv. In a mid-credits sequence, chainsmoking President Orlean (Meryl Streep) and baby-voiced, uncanny-valley-looking billionaire tech mogul Peter Isherwell (Mark Rylance) escape the planetary apocalypse on a space ship outfitted for the super-rich. They emerge, 22,740 years later, naked from their cryo-chambers and onto an uncharted planet, where CGI-rendered creatures proceed to eat Orlean alive, before closing in on the rest of the passengers.

Streep’s fate was signaled in an earlier scene when she asks Rylance’s character, who uses a predictive algorithm to look into the future, how she’s going to die. He tells her she will be eaten by “the brontaroc” but that “we don’t know what that means.” According to McKay, it was Streep’s idea that her character, a raging narcissist, would want to know how she would die. “We were shooting the scene with Rylance, Meryl and Jonah in the BASH control room for the second launch,” McKay said. “I’m like, ‘We should play around. Why don’t you guys talk about something? You never know. It could show up.’ And Meryl, who’s such a great improviser, says, ‘I want to know how I’m gonna die!’” As they riffed, they decided Jonah Hill’s White House Chief of Staff character Jason would “die in three days from eating tainted human flesh.” McKay posited to Streep, “What if you’re eaten by a creature?” “Mark, Meryl, and I kind of cleaned it up a little bit,” McKay said. “I think every time we said the name of the creature, it changed — and the take we used was a brontaroc. And then after we shot it, I said, ‘That’s really funny. We should end with her getting eaten by a brontaroc!’” At that point, McKay turned to VFX supervisor Raymond Gieringer, saying, “We’re adding a new beat. We’re creating a whole new creature.” He said that originally, another mid-credits scene was shot before being scrapped for the brontaroc ending. “The original ending was, ‘Oh, let’s start building our houses.’ And then someone says, ‘Oh, the pod carrying all the workers blew up.’ And then it was Mark Rylance going, ‘I’ll give anyone who builds me a house a billion dollars.’ And then the guy next to him was like, ‘I’ll give $2 billion.’ And then you realize they’re all billionaires.

“They’re going, ‘I’ll give $5 billion! $10 billion!’ And we just pulled out on that.” Meanwhile, in an end-credits scene, Jason (Hill) is shown emerging from the comet’s destruction as the last man standing on Earth, before taking a selfie amid the ruins. The idea came to McKay while filming the movie in Boston. “What if Jason Orlean, who you could argue is maybe the most despicable character in the movie — what if he’s the last guy on Earth?” That particular day of the shoot in late 2020 was freezing cold. “It was ice cold; it was the coldest day of the entire shoot,” McKay said. “And poor Jonah,” McKay said. “We’re, like, ‘All right! Get in the hole.’ And it was misery.” McKay turned to Hill, while filming on a parking lot, and said, “‘Jonah, I’ve never done this in my life. But if you get this on one take, I won’t do another take.’ And then I went behind the monitor, and I was like, ‘I shouldn’t have said that.’ Because I always get a second or a third take,” McKay said. “And then Jonah improvised the beat about ‘Like and subscribe, I’m the last man on Earth!’” Which is the ending as you see it in the movie. “Don’t Look Up” is now streaming on Netflix. Sign Up: Stay on top of the latest breaking film and TV news! Sign up for our Email Newsletters here.