Beware Boiúna (2026): Cast, Story and Release Details

Prepared by Movies Dock Editorial

Beware Boiúna is a 2026 horror thriller set in the Amazon, where a medical mission becomes a desperate fight for survival after an enormous ancient predator awakens. Directed by Mike P. Nelson, the film features Logan Marshall-Green, Kiana Madeira and Jessica Rothe in a creature-driven story of danger, nature and human endurance.

Beware Boiúna brings a classic creature-feature setup into the Amazon rainforest. The 2026 horror thriller follows a medical mission that faces a catastrophic threat when an enormous ancient predator emerges from the wilderness.

Directed by Mike P. Nelson, the film combines survival horror with an animal-attack premise. Its international production connects Germany, the United States of America and Colombia, while the story is told in English and Portuguese.

Beware Boiúna movie details

Story without spoilers

The film centers on a medical mission operating deep in the Amazon. Its work is disrupted when Boiúna, described as a colossal ancient predator, awakens and moves to reclaim her domain.

With the rainforest presented as a place where nature holds absolute power, the mission turns into a struggle to stay alive. The story’s central conflict pits a group of people engaged in humanitarian work against a gigantic snake in an environment that offers little control or safety.

What to expect

Beware Boiúna is positioned as a survival-focused horror thriller built around a giant-snake threat. The supplied genre and keywords point to animal attack, creature-feature and rainforest-survival elements, with the Amazon setting providing the main backdrop for the danger.

The premise suggests a concentrated battle between human vulnerability and a powerful predator, while the medical-mission context gives the characters a practical reason to be in the isolated environment. The film has a listed runtime of 1 hour and 44 minutes.

Cast and creative team

Logan Marshall-Green plays Brennan Malloy, with Kiana Madeira as Lena and Jessica Rothe as Alli. The cast also includes Jackson Bews as Shawn, Juan Pablo Shuk as Miguel, Will Close as Callum, Vicente Peña as Pedro, Jaime Newball as Raúl, Mateo Moreno as Diego and Nelson Camayo as Guilherme.

Mike P. Nelson directs and shares writing credit with Alan B. McElroy and Tony Giglio.

• Logan Marshall-Green as Brennan Malloy
• Kiana Madeira as Lena
• Jessica Rothe as Alli
• Jackson Bews as Shawn
• Juan Pablo Shuk as Miguel
• Will Close as Callum
• Vicente Peña as Pedro
• Jaime Newball as Raúl
• Mateo Moreno as Diego
• Nelson Camayo as Guilherme

Release and production context

Beware Boiúna is listed as a 2026 release with a release date of October 1, 2026. It is classified as a horror thriller and has a runtime of 1 hour and 44 minutes. The production countries are Germany, the United States of America and Colombia, and the spoken languages are English and Portuguese.

The listed production companies are Constantin Film, JB Pictures, Jaguar Bite, North.Five.Six. and Lionsgate.

Production companies: Constantin Film, JB Pictures, Jaguar Bite, North.Five.Six., Lionsgate

Beware Boiúna official trailer

Watch the official trailer on YouTube

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With its Amazon setting, humanitarian-mission premise and ancient giant-snake antagonist, Beware Boiúna is built around a clear survival-horror concept. Its appeal will depend on how viewers respond to creature-driven danger and isolated rainforest stakes, but the supplied details establish a focused genre setup and an international cast and production.

Film data:
TMDB · IMDb