Director Mike P. Nelson aims to elevate the giant-snake horror subgenre with his upcoming film, Beware Boiúna, a survival thriller set and filmed in the Amazon rainforest. Nelson, known for 2025's Silent Night, Deadly Night, expressed a desire to move beyond the often comedic or campy portrayals of giant snakes in film, with the exception of the 1997 original Anaconda, which he acknowledges is also something of a joke.
Unlike lighthearted adventure-horror fare, Beware Boiúna is described as a grounded and gritty experience. The narrative follows the fury of a mythological, truck-sized serpent unleashed upon those who threaten its fragile ecosystem. Screenwriter Alan B. McElroy's script reportedly pulls no punches, with no characters deemed safe, and Nelson's direction aims for brutal, unflinching detail.
Filming in the Amazon
The production faced the logistical challenge of filming in the remote Peruvian rainforest, with principal photography largely taking place in the Colombian jungle. Despite initial considerations for shooting in various jungle locations globally, Nelson insisted on authentic Amazonian settings. Producer Jeremy Bolt scouted the location, and Nelson's subsequent visit confirmed the necessity of filming in the actual Amazon.
Nelson found the Amazon to be a challenging but manageable environment for filmmaking, crediting an exceptional crew. The film's conservationist theme, which sees the mythical snake Boiúna protecting the rainforest from exploitation, reportedly aided in gaining access to sacred indigenous lands and the cooperation of local communities.
While acknowledging the potential dangers of Amazonian wildlife, Nelson noted that the environment is not inherently malicious. The crew did engage a snake wrangler, who served as a handler for all dangerous creatures and was considered the "MVP of the shoot." Despite precautions, close calls did occur, including an encounter with a Brazilian wandering spider, whose venom can cause severe effects. One cast member was bitten by a tarantula, though this was not life-threatening.
Bringing Boiúna to Life
The film's depiction of Boiúna, a mythological large black snake from Brazilian folklore, is a truck-sized serpent that does not shapeshift in this iteration. The creature was realized through a combination of practical and visual effects. To aid actor reactions during filming, the production utilized a large cardboard cutout of the snake's head and a painted black HVAC duct dragged through the environment to simulate its presence and movement.
Environmental manipulation also played a key role in achieving realism. The crew constructed falling trees and debris to simulate the snake's impact and used a rigging system to hoist an actor 40 feet into the air to depict a scene where a character is eaten. A cannon filled with debris was employed to simulate the snake emerging from the trees.
Despite the use of CGI for the creature, the production's efforts in creating a tangible environment and eliciting grounded performances from the cast contribute to Beware Boiúna's attempt at a realistic portrayal. The film is set to release in theaters on October 2.