By George & Josh Bate
When he premiered his inventive remake of Silent Night, Deadly Night as a secret screening at last year’s Fantastic Fest, director Mike P. Nelson delivered one of the biggest surprises of 2025. A year later, Nelson returns to Fantastic Fest for a decidedly different and admittedly less novel horror outing, a Jaws-esque creature feature that, once it gets going, proves to be a nail-biting exercise in dread.
Beware Boiúna follows a team of young doctors, including Alli (Jessica Rothe), who embark on a humanitarian mission to the Amazon rainforest to provide medical supplies and care to those in need. While traversing the jungles and waters of Columbia, Alli and local Lena (Kiana Madeira) cross paths with Brennan (Logan Marshall-Green), a man whose motives for being in this corner of the world are less altruistic, to say the least. To make matters worse, their arrival seems to awaken an ancient predator named Boiúna, a vicious 100-foot-long, 3.5-foot-wide snake, meaning they now need to contend against enemies both human and animal alike.
It is difficult to make a giant snake horror movie without conjuring thoughts of Anaconda. The 1997 film was intended to be a serious creature feature, with the actors playing their dramatic roles with straight faces, but it eventually was embraced as a campy cult classic, with plenty of over-the-top dialogue and silly moments to laugh at. With Beware Boiúna, Nelson treats the barebones of this premise far more seriously and, in turn, creates a film more likely to generate gasps than laughs.
But Nelson makes the audience wait quite some time until its titular beast wrecks havoc on our protagonists. The first act of the film unfolds far too slowly and is so strikingly absent of Bouina that one could be forgiven for thinking that what they are watching is indeed a giant snake horror movie. The set-up lays the groundwork for the characters’ arcs and establishes a bit of buy-in to ensure their deaths hit harder when they inevitably come along, but Nelson’s film requires a jolt.
That jolt eventually comes in the form of the snake itself. Whereas the bulk of the first half plays like a survival thriller in the Amazon forest, the remainder of the film operates like a giant snake movie and, in turn, lives up to its billing.
Nelson treats Boiúna like Spielberg treated Jaws, relying on suspense and mounting dread, rather than on-screen carnage, and recognizing that, in creature features, oftentimes less is more. The massive, pitch black snake slithers and sneaks around in the periphery, yet only rarely appears in clear lighting and in the center of the frame. As Nelson clearly understands that humans’ imaginations are scarier than anything reality could have to offer, the filmmaker allows his audience to fill in the gaps about where the snake is at any particular time and what the snake truly looks like.
Nelson’s decision to play his giant snake movie for drama and thrills, rather than campy laughs, goes hand-in-hand with his assured handling of the film. Featuring beautifully crisp greens and blacks, his film benefits immensely from raw, handheld camera work and an on-location shoot along the Amazon River.
Audiences can always tell when a movie like this is filmed on a soundstage and when it is filmed in the heart of nature itself, and Beware Bouina is firmly the latter. The characters look dirty, greasy and sweaty, the boat is a far cry from a glamorous vessel traversing the waters of Columbia, and the actors across the board authentically sell the fatigue, desperation, and griminess of what it would be like to be in this position.
All of these seemingly menial details amount to a film that immerses its characters and audiences in the unforgiving nature of the jungle. Bookending his film with scenes that shine a spotlight on the illegal gold mining that plagues this region, Nelson uses his giant snake movie to comment on the unwieldiness of nature. It doesn’t owe anything to anyone and, if exploited, has every right to strike back.
In this case, nature’s retaliation comes in the form of Bouina, who is more xenomorph than anaconda. The stark black aesthetic aside, both Boiúna and the xenomorph share a quiet, lurking menace that can suddenly erupt into full-fledged chaos at any time. The climax of the film is very much inspired by Aliens, all the way down to a character using a yellow piece of machinery that looks eerily like the work loader Ripley uses in James Cameron’s 1986 classic.
Perhaps most reflective of Nelson’s more grounded approach to a creature feature is how unpredictable it is. Consistent with his aim to portray nature as firmly in control and deprive the human characters of much of their autonomy as a result, major players in the story are fair game to succumb to the harshities of the jungle or Bouina herself at any given time. Nelson makes it clear to his audience that no one, regardless of their billing or status in the industry, is safe from an unexpectedly premature exit.
Reliable genre veterans Jessica Rothe and Logan Marshall-Green make for capable performers, as always, but it is Kiana Madeira who shines in the film. Both Madeira and her character Lena steadily grow into film as the fight for survival amplifies her intensity and determination. Although her central journey to be reunited with her lost brother fails to break new ground, Lena serves as the film’s most interesting character, largely due to her being more well-versed in the ways of the jungle and cautious of what it means, even for well-intentioned people like the traveling doctors, to encroach upon its territory.
In this sense, Beware Boiúna packs straightforward, yet fairly interesting commentary about the need to leave nature alone. Although never explicitly stated, the film implies that Bouina’s wrath comes about as a result of the arrival of both Rothe and Marshall-Green’s groups. One is well-intentioned, the other is not, yet they both find themselves in the middle of the same daring scramble for survival. It doesn’t take a genius cinephile to pinpoint what Nelson and company are trying to say about the state of the world, exploitation of nature, and climate change, but they somehow pull off the messaging nonetheless.
Not offering much in the way of novelty for much of its runtime, Beware Boiúna approaches iconic status with a scene in its final act. Those who have seen the poster for the film will know that Madeira’s character, at some point in the film, becomes submerged up to her face in thick, muddy water. The way this scene pans out in the film itself is nothing short of spectacular and is easily the highlight of the 90-minute creature feature. In addition to Boiúna proving more frightening than ever in this scene, the layered blacks of the muddy water and the black snake lurking within them gives this sequence a striking visual identity, made all the more noteworthy by its juxtaposition to the vibrant greens of the surrounding jungle.
VERDICT: 6/10
Making its world premiere at this year’s Fantastic Fest, Beware Boiúna finds filmmaker Mike P. Nelson (Silent Night, Deadly Night, Wrong Turn) taking a decidedly more serious and less campy approach to a giant snake movie. Operating more like a drama set in the Amazon for much of its first act, the creature feature takes far too long to get going and embrace its status as both a survival thriller and creature feature. However, once it does, the film comes alive (and the characters do the opposite).
Capturing the raw, unforgiving nature of the jungle with an intimate, grimy on-location shoot and clever use of handheld camera work, Nelson further grounds his film by ensuring that no character, however prominent they may be, is safe from the elements or Boiúna herself. This willingness to kill off any character at any time affords the film with a certain unpredictability that lends itself nicely to Nelson’s more sobering approach to a creature feature. Throughout this journey, Kiana Madeira shines with a capable, assured, and physical performance as a character who steadily grows into the story as the film’s runtime progresses. Madeira is also at the heart of the film’s best sequence, a harrowing swim in thick, muddy, black water surrounded by a 100-foot snake, that could very well be regarded as one of the more iconic horror movie scenes come the end of the year. Treating Boiúna more like a xenomorph than Anaconda and taking a page out of Spielberg’s Jaws by knowing that less is more in these kinds of films, Nelson makes the titular creature a frightening, ominous presence lurking over the entire narrative. The selectivity of its on-screen appearances make glimpses of it from afar or in between bushes all the more effective.
Beware Boiúna may struggle to break free of its sluggish first act, but, once it does, it makes for a nail-biting, albeit fairly routine, creature feature. Now, with four feature films under his belt, Nelson has tackled a post-apocalyptic action thriller, a folk horror slasher, a remake of a beloved classic, and now a giant snake movie. While not as strong as last year’s Silent Night, Deadly Night, Nelson’s latest work demonstrates that he can seamlessly operate within the confines of multiple sub-genres of horror and excel at doing so.
Beware Boiúna made its world premiere at this year’s Fantastic Fest. The film will be released in theaters on October 2, 2026, courtesy of Lionsgate.