Beware Boiuna (2026) Review: A Folklore Monster Stalks the Amazon

This Beware Boiuna review starts with a simple pitch: doctors, a remote jungle and a giant predator out of local legend. Director Mike P. Nelson turns that setup into an R-rated action-horror film that leans hard on atmosphere. It is a modest creature feature, but it has some real bite.

Beware Boiuna Review: The Story So Far (No Spoilers)

The Beware Boiúna plot follows a team of doctors who head into the Amazon rainforest on a local medical mission. The trip is meant to help people, not to hunt anything. Yet the group soon senses that not everything in the jungle welcomes them.

Their arrival attracts Boiúna, an ancient and enormous predator drawn from regional folklore. That is as far as we will go here. The film spends its first act setting up the team, the location and the growing unease before the danger gets close.

The film is written by Tony Giglio, Alan B. McElroy and Nelson himself. It runs 104 minutes and is rated R for bloody violent content, some grisly images and language.

What Works in Beware Boiúna

A setting with real texture

The Colombian Amazon is the star here. Critics have singled out how closely the film engages with its location, and Slant Magazine called it a rip-roaring creature feature. Using local folklore gives the monster a sense of place that a generic jungle beast would lack.

Scares that land

TheWrap described it as a really scary movie, and the horror side of this action-horror blend is where it is strongest. Nelson builds dread out of dense foliage, dark water and the sense of being far from help. If you enjoy the horror movie reviews we publish, the mood will feel familiar and effective.

The action side also gives the story some momentum. The film moves briskly, and its monster-in-the-wild premise is easy to follow.

Beware Boiúna Cast and Performances

The Beware Boiúna cast is led by Logan Marshall-Green as Brennan Malloy, with Kiana Madeira as Lena and Jessica Rothe as Alli. Jackson Bews plays Shawn, Juan Pablo Shuk plays Miguel and Will Close plays Callum.

This is a genre ensemble, so the actors mostly work in service of tension rather than deep character study. Marshall-Green brings a steady, weathered presence to the lead role. Madeira and Rothe give the group some warmth, which helps when the jungle turns hostile.

The weakness is not the performers but the material. The characters fit familiar types, and the script rarely gives the cast room to surprise us.

Where Beware Boiúna Stumbles

Reception has been mixed. Metacritic shows a Metascore of 49 from 8 critics, while Rotten Tomatoes lists 58% from 60 reviews and a 68% audience score. Those numbers match what we saw on screen: fun, but uneven.

Metacritic's summary says the film aims for a gritty 1970s-style thriller but lacks the substance to match. One critic found it overlong and felt the title creature appears too rarely. Another said it adds little new to the genre, with familiar scares and jump cuts.

We agree on the main points. For a monster movie, the monster is held back more than it should be. At 104 minutes it does not feel bloated, but some stretches are padding between the best set pieces.

Is Beware Boiúna Worth Watching?

Yes, if you want a lean, atmospheric creature feature and can forgive a thin script. It will not redefine the genre, but it offers a scary jungle setting, a distinctive piece of folklore and solid work from Mike P. Nelson behind the camera.

The film is best seen on a big screen with a crowd, where the jumps work better. Audiences have been warmer than critics so far, which suggests it plays better as a night-out thriller than as a serious horror statement. For more in this vein, browse our action movie reviews or the fierce survival drama Razor (2026) review.

The Beware Boiúna release date in US theaters is October 2, 2026, via Lionsgate. You can find cast and credits on Bloody Disgusting's film page.

Who Will Enjoy Beware Boiúna

• Fans of creature features who like a monster rooted in real folklore.

• Viewers who want a short, R-rated jungle horror ride with plenty of tension.

• Anyone curious about Mike P. Nelson's work and a fresh Amazon setting.