We came into this one ready to talk about snakes. Well, one snake. As Arthur put it, “one big giant ass snake,” and Meaghan added that it “could be the size of a thousand others put together.“
Beware Boiúna, the new creature feature from director Mike P. Nelson, hits theaters October 2, and we got to see it a little ahead of time (lucky us). If you caught our spoiler-free interview with Mike, you know the behind-the-scenes stuff; this is the actual review.
What Is Beware Boiúna About?
A team of doctors heads out on a medical mission along the Amazon River, and it soon becomes clear that not everybody, or everything, is happy to see them. Their arrival draws the attention of a predator: the Boiúna. That’s just the start.
The snake itself is basically a titanoboa, the kind of thing that existed millions of years ago. What makes it fun is that it doesn’t discriminate. Arthur said it best: the snake “doesn’t give a fuck” about who it’s killing.
That means far less safety for the characters than you’d expect, and you learn that early. Meaghan’s tagline keeps it simple:
Stay out of the jungle. Leave nature alone, guys.
Beware Boiúna Cast: Jessica Rothe, Kiana Madeira and Logan Marshall-Green
This one has a stacked cast. Jessica Rothe plays Alli, and Meaghan is still holding out hope for a third Happy Death Day. Kiana Madeira plays Lena; most of you will know her from the Fear Street trilogy on Netflix. Then there’s Logan Marshall-Green as Brennan. Meaghan has followed him since The O.C., while Arthur knows him from Upgrade.
Will Close plays Callum, a British doctor on the expedition. Juan Pablo Shuk plays Miguel, who more or less runs the mission, and Jackson Bews plays Shawn, Brennan’s brother.
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Filmed in the Amazon, and You Can Feel It
Our first impression? Shooting on location shows. They are on the river, deep in the jungle, sweating through the heat. Arthur called it “gritty” and “raw“; you really feel like you are there with them. Meaghan agreed it’s immersive, thanks to a cast and crew who committed to very uncomfortable conditions.
That commitment started before a single shot. Mike told us they had to ask permission to film on land near Leticia, which led to a ceremony with an Amazonian healer, a fermented corn and pineapple drink called chicha, and a blessing that named Mike “the father” of his crew. The weather had its own plans too. A flash flood wiped out the illegal mining set, so they shot it a different way, and now Mike can’t picture it any other way.
Arthur also loved the half-documentary, guerrilla-style shots, including the shaky handheld moments in the jungle. Meaghan’s favorite? The grime. She is tired of movies where everyone’s hair looks perfect after days of torment.
Why does everyone’s fucking hair look so good?
Not here. Kiana Madeira spends a lot of time soaked, and yes, she’s in that mud pit from the poster.
A Creature Feature That Takes the Boiúna Legend Seriously
Mike told us he didn’t want to make a typical creature feature, because the subgenre has a stigma of being silly. Sure, you have Jaws and Jurassic Park, but a lot of giant snake movies (see the Anaconda franchise) get kind of dumb. This one doesn’t, and halfway through it changes direction in a way we didn’t see coming.
There is a whole folklore behind the Boiúna, which keeps the story grounded. The film also opens on an illegal gold mining operation, and Meaghan liked that it carries a real message about what humans are doing to the rainforest. The snake isn’t just there to eat people. In her words, it’s there to say, “Can you fuck off?“
The other big win is that the snake isn’t stuck in the water. It shows up in the jungle, in a machinery yard, by day and by night, so you actually get to see it. As Meaghan pointed out, “It’s not a shark film.” After The Devil’s Mouth, where characters just sit up on a rock to stay safe, that difference matters.
In Beware Boiúna, no one is safe.
Is Beware Boiúna Scary? Our Scare Factor and Rating
Using our scare factor system, we both put this one in the Fun and Wild category with Solid Scares. It’s not terrifying, but a few shots hit hard, especially once you get a better look at the snake. The first clear shot of its head rising out of the water, half in shadow, looks great. Credit to the digital effects team.
Nobody is safe. Forget Anaconda. This snake means business.
Meaghan gave it a 7.5 for the enjoyment, effects, style, twist, and committed cast. Arthur went with an 8.
Yes, you should go see it on the weekend and have fun with it.
Catch it in a theater if you can.
Gary, our resident ghoul, has a message: You’ve been warned. Minor spoilers ahead.
Beware Boiúna Spoilers: The Boat, the Brother and That Twist
The doctors run into Brennan and Shawn, developers who seem to be pushing a road or some kind of project through the area. Alli is not a fan. After a tense night at the bar, she tries to sabotage their boat, which Meaghan called “a really poor decision.” Lena, who is also searching for her missing brother Jorge, catches her in the act at the same moment Shawn does. A fight breaks out, Shawn hits his head and dies, and the women dump his body in the water.
A kid in the forest saw everything. Brennan gets the story and sets out for revenge, no authorities involved. The medical crew detours to avoid him and ends up right in the Boiúna’s territory, home to an illegal mining and logging operation. From there the snake kills miners, locals, doctors, and anyone else in its path.
She sees you, she spots you, you’re probably fucked.
Meaghan said.
Arthur’s favorite part is the practical work. The explosions are real. People really fall through structures and run across a disintegrating plank. When the Boiúna tosses a character into the air, that’s a real stunt with the snake added digitally afterward. Arthur still can’t shake the scene where a man harpoons the snake, gets caught on the line, and is dragged behind it, dead. “That’s fucked up.”
Then there’s the twist. We won’t name it, but a character switcheroo halfway through had us looking at each other like, “What the fuck just happened?” Meaghan put it perfectly: when a giant animal movie can still surprise you, that’s an impressive feat.
Mike P. Nelson has already brought new life to Wrong Turn and Silent Night, Deadly Night, and he is now attached to direct the next Saw. Up next for us is Whalefall on October 16, and this packed horror year shows no sign of slowing down.
Beware Boiúna (2026)
Directed by Mike P. Nelson · 104 min · R
Beware Boiúna drops a group of doctors into the Amazon, right where an ancient giant snake has decided she's done sharing her home. Mike P. Nelson directs Kiana Madeira, Jessica Rothe, and Logan Marshall-Green in a creature feature rooted in local folklore and shot on location in Colombia, with real explosions, real stunts, and nobody guaranteed to make it out.