Back in 2004, the British zombie comedy Shaun of the Dead arrived on U.S. shores billing itself as a loving homage to George A. Romero’s beloved Dawn of the Dead, the follow-up to his groundbreaking Night of the Living Dead. Smash cut to 15 years later, and both Dawn and Shaun are confirmed genre classics, with the latter serving as the launching pad for the careers of stars/geek icons Simon Pegg and Nick Frost and director Edgar Wright, who previously collaborated on the cult U.K. series Spaced. In the ensuing years, all three have spoken extensively about the movie via commentary tracks, making-of featurettes and public appearances, to the point where you might think there’s no longer anything left to learn about the film that’s spawned a thousand zom-coms. Well... think again. When Yahoo Entertainment sat down with Pegg earlier this year, he came armed with five facts you probably never knew about Shaun of the Dead. (Watch our video interview above.)

1. There’s a reason slow-moving zombies are terrifying.

When Romero was making his pioneering zombie favorites, the walking dead only moved at a slow and steady pace. But by the time that Wright, Pegg and Frost were making Shaun, zombies had acquired frightening busts of speed in films like 28 Days Later and Zack Snyder’s Dawn of the Dead remake. Previously a zombie originalist, Pegg now says that’s he’s come around on their lightning-quick descendants. “I’m not the purist I used to be — I’ve seen fast-zombie things that I’ve enjoyed,” the actor says, pointing to the 2016 South Korean cult favorite Train to Busan. But there was never a world in which Shaun would have made the switch, and not just because they were trying to remain true to Romero’s vision. Pegg argues that quicker creatures would have undermined the dramatic metaphor of a person — and entire society — caught in the grip of stagnation, which runs beneath the movie’s comedy. “There’s something incredibly creepy about the shambling dead. They’re more of an effective metaphor for death when they just sort of come slowly. That’s what death is — death doesn’t always just run at you.”

2. The movie’s most complex scene was the very first one filmed.

Few things prove a first-time filmmaker’s mettle more than executing a lengthy single-take sequence on the very first day of a shoot. On the other hand, the failure to pull it off could bode poorly for the rest of production. That’s the difficult position that Wright put himself in by earmarking two of Shaun’s most complex scenes — a pair of tracking shots following Shaun to his corner bodega, pre- and post-zombie outbreak — for Day 1. “We did the zombie version, and then that afternoon we went back and did the pre-zombie version,” Pegg remembers. “That was Edgar showing the crew his mettle. It was like, this is what we’re going to be doing for the next three months.”

3. Coldplay’s Chris Martin does not play a zombie in the movie.

It’s the “fun fact” that won’t die: Coldplay frontman Chris Martin appears as a zombie in the big crowd of brain-eaters seen during the film’s climax. Time to update those IMDb-assisted trivia posts, because Pegg is here to set the record straight once and for all. “Chris is not in the film as a zombie. He’s not!” The confusion might stem from the fact that Martin does appear, as himself, in a TV clip at the end of the film showing his support for a zombie charity program called Zombaid. But he never put on the zombie make-up. “Chris and [Coldplay guitarist] Johnny Buckland came along and sent themselves up as zombie sympathizers,” Pegg explains. “But no, Chris Martin was not a zombie in Shaun of the Dead. Please stop writing that in lovely articles online.”

4. The bloody ending is a gruesome homage to George A. Romero.

You’ve heard of gross-out comedies? Well, Shaun of the Dead gets seriously gruesome in its climax, when Shaun’s rival, David (Dylan Moran), has his guts scooped out by an army of hungry zombies. “We had to have an evisceration as a tribute to George,” Pegg explains about that wild tonal shift. “I think George Romero as a filmmaker [created] a modern monster in the zombie. The zombie before George was a kind of voodoo-related thing. George brought in a little voguish cannibalism, added a bit of vampire mythology. Everything that’s followed since then owes a huge debt to him.”