Beware Boiúna Review: Creature Feature Slithers Without Enough Venom

Kiana Madeira and Jessica Rothe face a legendary Amazon serpent in a creature feature held back by slow pacing and a lack of fun.

When it was announced that the 2026 Fantastic Fest opening night lineup would include ‘Beware Boiúna’, it continued an exciting trend of creature features terrorizing the festival crowd on night one. Last year, attendees witnessed a rabies-infested chimp, Ben, tearing off faces and causing general mayhem in ‘Primate’ to kick off the genre film festival in Austin. This year, all I had to hear was “giant snake” to get me amped up for Boiúna’s antics. Unfortunately, the idea of a monster snake is much more exciting than the film we got.

In ‘Beware Boiúna’, Kiana Madeira and Jessica Rothe portray Lena and Alli, who work with a group of humanitarians on a medical mission in the Amazon. Much of the film is spent establishing the group’s goals and introducing their rivalry with Logan Marshall-Green’s Brennan Malloy and his brother, Shawn, portrayed by Jackson Bews. While the two groups are at odds, they eventually end up in the territory of the legendary “Boiúna”, a giant serpent who is extremely protective of her territory.

Slow Pacing Drains the Creature Feature’s Energy

Off the bat, the biggest problem with ‘Beware Boiúna’ is the absolutely dreadful pacing. The first section spends too much time setting up the characters and the setting, which wouldn’t be a problem if any of it were particularly interesting, but Alan B. McElroy’s screenplay moves at a snail’s pace while the audience waits for the monster snake to appear. Not only that, but it’s all played so seriously, and there’s hardly an ounce of fun to be had.

It’s a real shame too, as we’ve seen the comedic talents of Jessica Rothe at work in the ‘Happy Death Day’ franchise, and she’s a wonderful talent who is truly underutilized. Kiana Madeira’s Lena is a cool horror heroine and ‘final girl’ trope, and Madeira was able to defy some expectations of where the character is at in the beginning of the film. I think both leads are doing the best they can with the material they have here, but both are underserved by the material.

The actual monster also left a lot to be desired. Yes, Boiúna herself is at the very least quite large. But the shaky camera style and dark environments mean that the audience is never even given a truly clear look at the baddie snake. By the time the climactic battle was taking place, there was very little to even be invested in.

Director Mike P. Nelson’s previous film, ‘Silent Night, Deadly Night’, premiered at Fantastic Fest 2025 as a secret screening, and I overall had a pretty good time with it. So I know he has the ability as a horror director to have fun with the material. It’s unfortunate that with a concept like “giant snake” where it should be so easy to find fun, there’s just so little to be had.

Verdict

‘Beware Boiúna’ offers up some serviceable jumps and performances from its leads. However, dire pacing and a lack of any enthusiastic fun to be had left this snake without much venom in its bite.

Beware Boiúna releases in theaters on October 2, 2026.

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