Beware Boiúna Review: Amazon Creature Horror (2026)

The premise is lean and efficient. A team of medical volunteers, led by the weary but determined Brennan Malloy (Logan Marshall-Green), ventures deep into the Amazon to deliver vaccines to an isolated village. The group includes Lena (Kiana Madeira), a pragmatic doctor; Alli (Jessica Rothe), a sharp-tongued logistics expert; and a handful of local guides, including Miguel (Juan Pablo Shuk) and Pedro (Vicente Peña), who warn of ancient spirits better left undisturbed. When the mission disrupts a sacred site, the earth shudders, the river churns, and Boiúna - a colossal serpentine predator of legend - awakens to reclaim her domain. What follows is a nightmarish game of cat and mouse where the jungle itself seems complicit in the carnage.

Nelson understands that the most terrifying monsters are the ones you barely see. For the first act, Beware Boiúna operates like a creeping fever dream. The sound design is immaculate: the rustle of leaves, the snap of twigs, the low, guttural hiss that vibrates through the theater of your living room. Cinematographer Nicola Marsh (no relation to the legend, but a talent in her own right) frames the Amazon as a character - lush, indifferent, and claustrophobic. You can practically feel the humidity clinging to your skin.

When Boiúna finally reveals herself, the film shifts gears into a relentless survival thriller. The creature design is a standout, blending practical animatronics with CGI that respects the serpent's sheer, crushing weight. She is not a mindless beast; she is a goddess with a grudge, and every kill feels like a judgment. The set pieces are brutal and inventive - a river crossing gone horribly wrong, a collapsing canopy, a final stand in a flooded cave - each one escalating the stakes without overstaying its welcome.

The performances, however, are a mixed bag. Marshall-Green anchors the film with a lived-in weariness; his Brennan is a man carrying the weight of past failures, and you believe every grimace. Kiana Madeira brings a quiet intensity to Lena, though she's underserved by a script that occasionally reduces her to the "voice of reason." Jessica Rothe, who was a scream queen revelation in the Happy Death Day films, is saddled with the most thankless role here - Alli exists mostly to panic and deliver exposition. The local cast, particularly Juan Pablo Shuk as Miguel, injects much-needed authenticity and gravity, grounding the supernatural chaos in genuine cultural respect.

Where the film falters is in its pacing and dialogue. The first act takes its sweet time, which is fine for atmosphere, but the middle stretch sags under the weight of repetitive arguments and a subplot about a stolen artifact that goes nowhere. Lines like "The jungle doesn't forgive" land with a thud, and the film occasionally confuses loud noises for real scares. At 104 minutes, it feels slightly bloated; trimming ten minutes of bickering would have sharpened the tension considerably. The TMDb rating of 6/10 feels about right - it's a solid effort that never quite reaches the heights of The Descent or Prey, but it's far from a misfire.

Pros

• Stunning, oppressive cinematography that makes the Amazon a living, breathing threat
• Impressive practical creature effects and sound design that maximize dread
• Logan Marshall-Green's committed performance anchors the chaos
• Respectful incorporation of Indigenous lore without becoming preachy
• Several genuinely nerve-shredding set pieces

Cons

• Clunky, on-the-nose dialogue that undermines the tension
• Uneven pacing; the middle act drags before the finale kicks in
• Underdeveloped supporting characters, especially Jessica Rothe's Alli
• A few CGI shots don't hold up to the otherwise excellent practical work

Beware Boiúna is a sweaty, suspenseful ride that honors its B-movie roots while aiming for something more mythic. It doesn't always hit the mark - the script could have used another pass, and a few characters feel like fodder - but when Boiúna strikes, you'll be too busy holding your breath to care. For horror fans craving a creature feature with teeth, this is a worthy addition to your October watchlist. Just don't expect to sleep with the lights off.