The giant-snake movie has always been a punchline. Director Mike P. Nelson knows it, and he is not shy about saying so. “Look at the giant snake movies that have come before us,” he told Polygon. “With the exception of Anaconda, they’re kind of jokes.” His answer to that problem was not a bigger star or a slicker creature. It was mud, humidity and a film crew hauled into the rainforest.
Beware Boiúna is a survival horror film directed by Nelson, whose previous credit is 2025’s Silent Night, Deadly Night. The screenplay comes from Spawn writer Alan B. McElroy, working from a story he developed with Tony Giglio. Kiana Madeira, Jessica Rothe and Logan Marshall-Green lead a humanitarian medical expedition that wakes something enormous. In Brazilian mythology, the Boiúna is a large black snake with shapeshifting powers. The film’s version never changes form, but it is roughly the size of a truck, and it hunts loggers, gold miners and anyone else threatening the ecosystem it guards.
The story is set in the Peruvian rainforest. The shoot happened mostly in the Colombian jungle, near Leticia along the Curuçá River, and it nearly did not happen there at all. The studio priced out jungle stand-ins around the world before Nelson pushed back. Producer Jeremy Bolt scouted the Amazon first, Nelson followed, and the decision took minutes. “As soon as they started taking us around, showing us the boats, taking us down the actual Amazon River, showing us some of these jungle areas, I was just like, ‘It has to be here, dude.'” The film’s conservationist streak helped win over local communities, and elders blessed the production and opened up land the crew could never have reached otherwise.
Nelson refused to shoot the monster with tennis balls on sticks. Instead the team puppeted the environment itself:
- A long piece of HVAC ducting painted black, dragged through undergrowth and pulled into water to suggest something huge moving past the cast
- A huge cardboard cutout of the snake’s head for actors to play against in some scenes
- Full-size trees rigged to fall, crash and throw debris into the air
- A purpose-built truss in the middle of the jungle capable of yanking a performer 40 feet upward — the trailer’s most brutal death is a real stuntman, not a digital double
- A debris cannon firing dirt out of the canopy to stand in for the serpent bursting through
The wildlife was less theatrical but more alarming. A snake wrangler walked about 10 steps ahead of the crew as a general handler for dangerous creatures and was later named MVP of the shoot. A Brazilian wandering spider turned up on someone’s umbrella during rain. Someone else was bitten by a tarantula. “Sure, everything there could kill you, but it’s not necessarily there just to kill you,” Nelson said.
The 104-minute film has its world premiere on the opening night of Fantastic Fest in Austin, Texas on September 17, 2026. Lionsgate releases it in US theaters on October 2, 2026.
