Beware Boiúna Fantastic Fest Review: An Incredibly Dull Creature Feature

Creature features don’t have a particularly high bar to meet as popcorn entertainment — usually, even if they’re not particularly good, they at least aren’t utterly boring. But the key word there is “usually.” Feeling like an Asylum rip-off of Anaconda but somehow far less fun, Beware Boiúna is one of the most joyless horror movies you will have the displeasure of seeing on cinema screens this year.

What is Beware Boiúna about?

Beware Boiúna follows a group of doctors on a humanitarian mission in the Amazon when they find themselves being pursued by a beast of mythology: a giant snake called Boiúna who is known by the locals as the protector of the rainforest. On paper, this should make for a fun monster movie, but every single element of this feels poorly executed.

Beware Boiúna Review

One of the biggest sins of Beware Boiúna is that it takes itself far too seriously. This is a movie about a giant snake. It doesn’t need to be a full-on comedy like 2025’s Anaconda, but there should at least be some semblance of camp or lightheartedness. Instead, we’re subjected to a film that’s just mean and unpleasant.

Beware Boiúna. Photo Credit: Courtesy of Lionsgate

And at an hour and 45 minutes, Beware Boiúna quickly starts to feel like a slog. There is an early action sequence in found-footage style with the Boiúna, but then it takes a full 45 minutes for the monster to reappear. And with the message, it’s clear that they’re going for the “people are the real monsters” approach, which is as dull and derivative as they come.

Even more infuriating is the fact that the film’s action is shot in a way that is borderline incomprehensible. The cinematography is so overly shaky and dark that you can hardly see anything in the first place, and in the kills, it feels like they barely hold a shot for more than a few seconds. Given that a lot of audiences come to creature features to see gore, this feels like a massive letdown.

To give some credit to the film, the visual effects to bring the mythological serpent to the screen are decent. There’s a lot of CGI, but it’s not distracting, and when they can work in a few practical tricks, it does wonders. But again, there’s no time to really admire the work of the effects artists because you don’t have enough time to see it.

The characters in the film are also terribly written. Granted, in the creature feature genre, you have to be used to the characters feeling somewhat disposable. They are there to be killed and/or eaten by the monster. But the backstories that these characters are given are generic and hammered in through expositional dialogue and forced emotional beats that will make you roll your eyes.

You can tell that the cast is trying their best with the material they are given, but they simply cannot elevate it. Kiana Madeira (Fear Street) shows some promise as a badass, but her character is awfully written. Jessica Rothe (Happy Death Day) feels like she is sleepwalking through her performance. No one in the cast is worse than Logan Marshall-Green (The Odyssey), though. He doesn’t even play the villain in an exaggeratedly fun way; he just seems bored and mad that he’s there.

Is Beware Boiúna worth watching?

It’s hard to screw up a movie about a giant snake so badly that it’s not fun to watch at all, but that is somehow what happened with Beware Boiúna. Mike P. Nelson fails to provide the audience with the bare minimum that they would be asking for when they buy a ticket to a creature feature, and because of that, it easily stands out as one of the year’s worst films.

Beware Boiúna is screening at the 2026 edition of Fantastic Fest, which runs September 17-24 in Austin, TX.