Based on a podcast (or Smodcast, to be precise) that—if the excerpt over final credits crawl is any indication—Kevin Smith and his partner could barely deliver because they were laughing so hard at their own inventiveness, “Tusk” tries to be scary, funny and profound all at once, and fails signally at each. It’s certainly strange, but among unwanted transformation movies comes closer to “Human Centipede” than “The Fly.” That is not a recommendation.

The movie begins self-referentially with a podcast featuring partners Wallace (Justin Long) and Teddy (Haley Joel Osment) finishing up their latest “Not See Party” show before Wallace flies off to Canada to interview a YouTube sensation. Unfortunately, when he gets there he finds that his guest has suddenly died. Fortunately he finds a scrawled bulletin board ad from one Howard Howe (Michael Parks), an elderly gent who promises a rent-free room for anyone willing to listen to his tales of an adventurous life.

According to Smith, the kernel of his script was a gag advertisement for free housing for anybody who agreed to wear a walrus suit for a couple hours a day. The movie turns that into something stranger and ultimately more sinister. Among the apparently tall tales that Howe, a soft-spoken fellow in a wheelchair, spins as Wallace looks over the amazing collection of souvenirs in his mansion is one recounting his being shipwrecked, with his only companionship on the rock he reached being a walrus he called Mr. Tusk—the creature that saved his life. It seems that Howe is looking to replicate that experience, the most fulfilling one he’s ever had, in the present, and Wallace represents but the latest attempt to do so.

It wouldn’t be fair to reveal to much about what happens from that point on, except that Wallace disappears and his girlfriend Allison (Genesis Rodriguez), as well as Teddy, come to Winnipeg to search for him. Eventually they’re joined by an oddball ex-detective of the Quebec PD, one Guy Lapointe, who relates that he’s been tracking Howe, whom he identifies as a prolific serial killer, for years. Together the trio will find out what happened to Wallace at Howe’s hand. The denouement might just bring Tod Browning’s “Freaks” to mind.

Much the talk about “Tusk” will probably surround the face that lurks behind Lapointe’s heavy makeup and absurd accent. He’s listed in the cast under the character’s name, but is actually played by a surprise guest star who seems to be having a wonderful time that only fleetingly elicits an equally enthusiastic audience response. But the cast members who really deserve mention are Long and Parks. The former at first is just doing his loopy hipster shtick, but he morphs into something more soulful as the piece goes on. And the latter follows up his recent parts in Tarantino movies and as the doc in Jim Mickle’s “We Are What We Are” with a finely-judged turn as an unhinged man with a big dream. As for Osment, one can only note that he’s certainly not the cute little tyke of “The Sixth Sense” anymore.

Technically “Tusk” represents an advance for Smith. Perhaps it’s the influence of cinematographer James R. Laxton, but the shots are actually well-composed and efficiently realized. Nonetheless Smith’s editing doesn’t show much improvement; individual sequences tend to ramble on a mite too long. Overall, though, the picture shows a degree of polish one doesn’t find in his earlier work, with Robert Kurtzman’s makeup effects deserving of special mention.

“Tusk” earns points for sheer audacity, but audacity isn’t enough.