Lionsgate released Beware Boiúna in United States theaters on October 2, 2026, a survival horror film directed by Mike P. Nelson and starring Logan Marshall-Green, Jessica Rothe, and Kiana Madeira.
The film follows a medical mission deep in the Amazon rainforest that spirals into a fight for survival when Boiúna, a colossal ancient predator, awakens to reclaim her domain. The official synopsis states: ‘Deep in the Amazon, a medical mission spirals into a fight for survival when Boiúna, a colossal ancient predator, awakens to reclaim her domain. In the jungle where nature holds absolute power, she decides who lives and who dies.’
The cast includes Logan Marshall-Green as Brennan Malloy, Jessica Rothe as Alli, Kiana Madeira as Lena, Jackson Bews as Shawn, Juan Pablo Shuk as Miguel, Will Close as Callum, Vicente Peña, Jaime Newball as Raúl, and Sergio Herrera. Rothe plays a medical student traveling with a humanitarian team, while Madeira portrays a Colombian-Brazilian deckhand searching for her lost brother.
Beware Boiúna was produced by Jeremy Bolt and Robert Kulzer, the producing team behind the Resident Evil franchise. The screenplay was written by Alan McElroy from a story he co-wrote with Tony Giglio. The film was produced by Constantin Film, JB Pictures, and Jaguar Bite.
The film had its world premiere as the opening night selection of Fantastic Fest 2026 on September 17 at the Alamo Drafthouse Theater in Austin, Texas. Director Mike P. Nelson and cast members Kiana Madeira and Jessica Rothe attended the screening.
The film carries an R rating for bloody violent content, some grisly images, and language. Its runtime is 104 minutes.
Director Mike P. Nelson said he wanted to approach the giant snake subgenre with a serious tone. ‘We definitely have a giant snake in this movie, but I don’t want it to be a giant snake movie. I want it to be a great movie with a giant snake in it. That was where we started building from,’ Nelson said during an interview with the Boo Crew podcast.
Nelson also said he deliberately avoided watching Anaconda before making the film. ‘I actually made a point not to watch Anaconda before I made this movie,’ he told Rue Morgue. ‘A lot of times, I will not watch the movies that are directly supposed to inspire the movie that I’m making. I’ll actually surround myself with other films that maybe fall into the same genre or outside the genre. No, you’re not going to watch Anaconda. You are gonna watch Jurassic Park. You are gonna watch Jaws. You are gonna watch Alien. You are gonna watch Tremors.’
Nelson cited William Friedkin’s Sorcerer as his greatest inspiration. ‘When I watched that, I was like, Oh my gosh. I wanna do something more like this, and what happens if I put a giant snake in it?’ he recalled.
Production took place on location in Colombia, including the Amazon rainforest and the Curuçá River, in late 2024. Jessica Rothe said shooting in the actual jungle shaped the performances. ‘Every single thing our characters were experiencing, we were also experiencing,’ Rothe told ComingSoon. ‘I mean, not being chased by a giant, scary-ass snake, but just how heavy the air is, the smells, the sounds, the fear of the unknown, of what’s deep in that jungle.’
Kiana Madeira described the physical demands of a key scene in which her character becomes trapped in quicksand. ‘It was fun. It definitely was fun,’ Madeira told ComingSoon. ‘I mean, it’s not like we had a pristine and clean film up until that point anyway, so by that point we were pretty used to being sweaty and dirty.’
Nelson spoke about the jungle’s role as an antagonist. ‘Not mincing words here: one of the things going into this movie that I talked with [our writer and producers about] creatively was, the jungle doesn’t give a f–k,’ he told SYFY Wire. ‘It doesn’t matter who you are as a character, as a person. Going into that environment, it’s there to survive as well. So, if you are in the wrong place at the wrong time, it might be your end. Ultimately, the jungle is an amazing place. It’s a beautiful place. But also, it’s unforgiving.’
Rothe described the title creature as an unpredictable force. ‘She is death that is coming for us all one day, and there’s no rhyme or reason to it,’ Rothe told SYFY Wire. ‘If you’re a good person, it doesn’t mean that you’re going to survive. If you’re a bad person, it doesn’t mean you’re going to die. That unpredictability gives such stakes to this film.’
Madeira said the script surprised her during her first read. ‘Even reading the script for the first time, I was gasping,’ Madeira told SYFY Wire. ‘I was like, They did not! As an audience member watching it, I hope they feel the same way. It’s ruthless. The jungle is ruthless. Like Jess said, it can come for anyone. It’s one of my favorite things about this film.’
Both Rothe and Madeira embraced the Scream Queen label during interviews. ‘It’s a fun entry point because you’ve got to have that vocal power to pierce through,’ Rothe told UPI. ‘I think that it’s such a fun title that I feel very honored to have been assigned to me or for people to use.’
Madeira said she and Rothe shared a similar work ethic. ‘Your commitment to take after take after take, that’s also how I love to work,’ Madeira told UPI. ‘You don’t feel silly going 100%. I think from the jump, our scenes together, we were like okay, we can really go there. We don’t have to feel embarrassed or shy.’
The film received mixed reviews from critics. As of October 2, Beware Boiúna held a 56 percent approval rating on Rotten Tomatoes based on 34 reviews, marking director Mike P. Nelson’s first Rotten score after an eight-year streak of Fresh ratings. The score later settled at 54 to 55 percent with additional reviews. On Metacritic, the film held a score of 49 based on 8 reviews, indicating mixed or average reception. The audience score on Rotten Tomatoes stood at 70 percent.
The Globe and Mail called it ‘the best giant-snake movie to come out over the past 12 months’ but added that it is ‘only sporadically a good, stupid time at the movies.’ IGN gave the film a 6 out of 10 and wrote that ‘appealing actors and a willingness to be somewhat unpredictable check the boxes for the movie to kinda-sorta deliver in terms of the expected basics.’
Slant Magazine gave a score of 63, noting that the film is ‘surprising both for how attuned it is to the rhythms of its setting and for how little interest it has in condescendingly exorcising our white guilt.’ RogerEbert.com gave a score of 38 and wrote that ‘there is one phenomenal sequence in the middle of this frustrating movie that’s almost worth seeing, but it only speaks to how much the rest of this creature feature doesn’t work.’
The film opened in wide release on over 1,100 screens but finished outside the domestic top ten at number 14, earning approximately $550,000 in its opening weekend, according to Fangoria. That figure represents a per-screen average of approximately $490. The opening weekend faced competition from the Colleen Hoover adaptation Verity and the Tom Cruise-led Digger.
The movie was originally filmed under the title Titan. Lionsgate later retitled it Boiúna: Legend of the Amazon before settling on Beware Boiúna in July 2026.
The Boiúna is a creature from Brazilian indigenous folklore, described as a colossal black serpent that lives in deep waters and is believed to be a shapeshifter. The film was inspired in part by the 2009 discovery of Titanoboa fossils in a Colombian coal mine, where vertebrae the size of softballs were unearthed.
Beware Boiúna is currently playing in theaters. The film is expected to arrive on premium video on demand in the coming weeks.