‘Beware Boiúna’ Brings a Legendary Jungle Predator to the Big Screen

The Amazon has supplied horror with no shortage of dangerous wildlife, but Beware Boiúna is going considerably bigger. Mike P. Nelson’s new creature feature turns one of Brazilian folklore’s most formidable legends into a full-scale monster movie, with Lionsgate releasing the film in US and UK cinemas in just a few days following its Fantastic Fest premiere.

Set deep in the Amazon rainforest, the story follows a humanitarian medical mission travelling along the Curuçá River when the group inadvertently awakens Boiúna, a colossal serpent drawn from regional mythology. What begins as an aid mission rapidly becomes a fight for survival as the creature reasserts control over its territory and those caught inside it are forced to contend with both the environment and the predator moving through it.

Nelson directs from a screenplay by Alan B. McElroy, based on a story by McElroy and Tony Giglio. The project reunites Nelson and McElroy after their collaboration on the 2021 Wrong Turn reboot, with the film having previously circulated under the working titles Titan and Boiúna: Legend of the Amazon before arriving at its final name.

Kiana Madeira, Jessica Rothe and Logan Marshall-Green lead the cast. Madeira is best known to horror audiences for Netflix’s Fear Street trilogy, while Rothe broke through as Tree Gelbman in Happy Death Day and Happy Death Day 2U. Marshall-Green’s genre credits include The Invitation, Upgrade, Devil and Prometheus.

The supporting cast includes Jackson Bews, Juan Pablo Shuk, Will Close, Vicente Peña, Mateo Moreno, Jaime Newball, Christophe de Geest and Nelson Camayo.

The mythology at the centre of the film comes from the legend of Boiúna, also known as Cobra Grande, a gigantic serpent said to inhabit the Amazon river basin. Rather than treating that folklore as a superficial monster hook, the production has framed the creature as an extension of the environment itself, placing human characters inside a landscape where they are very much not in control – always a great scenario for exciting cinema!

Principal photography took place in the Amazon region, including areas near Leticia in Colombia, with the cast and crew filming around river and jungle locations. Professional animal handlers were used on set because of the risks presented by venomous and poisonous wildlife native to the area.

Beware Boiúna made its festival debut at Fantastic Fest on 17 September and will open in US and UK and Irish cinemas through Lionsgate on Friday 2 October 2026.

Beware Boiúna trailer