On June 25th 2013, during the regular Kevin Smith podcast (SModcast #259) he and co-host Scott Mosier were laughing about an post they’d just seen on GumTree.com — a British classified ad website.

There was a listing from a man who claimed he’d spent three years alone on St Lawrence Island with only a walrus for company “whom I named Gregory”. He said he has never had such a fulfilling friendship with anyone, human or otherwise, and upon leaving the island was heartbroken for months. He was now offering free lodging at his house in Brighton with the only caveat being the lodger would have to dress, for two hours a day, in a “realistic walrus costume” that the man had constructed and “be a walrus”. Tasks would include making walrus noises, not speaking and catching the occasional fish. Smith and Mosier, amid fits of laughter, began riffing on this and suggesting that this is something that could turn very dark and nasty pretty quickly. And hey, it would also make a great horror movie.

They began creating a backstory for this man and his walrus obsession and how this twisted tale could play out. “We could make this movie for less than four-million bucks, man, the most expensive part would be the suit,” Smith says. Then they were off fantasy casting: “I’m going with John Cusack as the guy and James Franco as the lodger who gets sewn into the suit”.

Smith then told his Twitter followers to tweet “#WalrusYes” if they wanted to see their hypothetical turned into a film, or “#WalrusNo” if they did not. People were interested and the low-budget horror was made. And for a million less than Smith said it would cost. The result is a horror-comedy about a serial killer who, indeed, turns his victims into walruses. There was no Cusack or Franco but they did, however, get the excellent Justin Long as the guy who gets turned into a walrus, and Michael Parks as the marine-mammal obsessed landlord. Johnny Depp also appears as a detective tracking the missing victim. It’s a 21st Century Hammer Horror film or Tales of the Unexpected for the millennials.

Smith told The Hollywood Reporter, “The idea had quickly gone from a goofy, streamof- consciousness sketch in a podcast to an exercise in possibility and momentum, where I casually guided the whimsy of every artist’s first question (“What if…?”) toward the unruly and expensive moviemaking process — just to see how far it could go.

“What I love about all this is that a movie came from a podcast. It might be one of the first situations I ever heard of where that happened. I’m delighted by the fact that my new world of podcasts is now shaping my old world of film. New media nourishes old media and together, they produce some weird art. It’s very 21st Century.”

Indeed, if you go back and listen to the podcast (it’s still there online) what you are hearing is no less than the birth of a film. People goofing about, coming up with ideas, laughing and saying what they would like to see in a weird horror film. And just like that, a Kevin Smith film is made. Smith went on, via his blog, to write about the process of how they funded and made the film — that they eventually called Tusk — and it’s now going to be the first part of a True North Trilogy all set in Canada. Part two is a spin off (Yoga Hosers) featuring the two store clerks from Tusk who battle an ancient evil rising from beneath the town, with the help of Depp’s detective. The third film is entitled Moose Jaws, which has been described as – you ready? – “Jaws with a moose”.

Critics have been hugely divided on Tusk calling it “a twisted fairy tale”, “utterly disgusting”, “close to Human Centipede territory in gross-out-ness” and “an utterly bizarre, but weirdly compelling story”. It hasn’t taken huge amounts at the box office, but perhaps the real story is that it was made at all.

And for those wondering about the original advert, it turns out that it had been placed as a joke by Brighton resident Chris Parkinson. Smith flew Parkinson out to Canada to help make the film and gave him a producer credit. Imagine your little practical joke leading to that.