Beware Boiúna

THE JUNGLE BELONGS TO HER

They came to the Amazon to help people.

The Amazon already had something else waiting.

In Mike P. Nelson’s Beware Boiúna, a medical mission deep in the rainforest turns into a fight for survival when the group’s presence draws the attention of an enormous predator.

Her name is Boiúna.

And the jungle belongs to her. 

Lionsgate’s official synopsis describes Boiúna as a colossal ancient predator that awakens to reclaim its domain.

Not invade one.

Reclaim it.

That distinction matters.

The people are the newcomers.

The creature was there first.

And in this jungle, nature—not the visitors—decides who survives. 

The film is led by Logan Marshall-Green, Kiana Madeira and Jessica Rothe.

Marshall-Green plays Brennan Malloy, while the current cast also includes Will Close as Callum, Jackson Bews as Shawn, Juan Pablo Shuk as Miguel, Vicente Peña as Pedro, Jaime Newball as Raúl, Mateo Moreno as Diego and Nelson Camayo as Guilherme. 

Nelson approached the movie as more than a simple giant-snake picture.

In discussing the project, he has emphasized wanting the creature to feel tied to the environment and mythology surrounding it rather than functioning as a random oversized animal dropped into the plot. 

That approach is visible in the premise.

Boiúna isn't wandering around looking for a place to cause trouble.

The humans enter her territory.

And the movie treats the rainforest as part of the threat rather than scenery behind it.

The production actually went into the environment.

Beware Boiúna was filmed on location in Colombia, standing in for the Brazilian Amazon setting. Nelson has discussed how shooting in the real jungle changed the feel of the production and gave the movie a scale and physicality that would have been difficult to reproduce on a controlled stage. 

That physical approach extended to the creature work.

Nelson used practical methods to help performers understand the snake’s size and movement, including dragging a large weighted object through the jungle to simulate the displacement of an enormous body and using oversized visual references for eyelines. 

The actual creature is, of course, larger than anything naturally moving through those locations.

But the goal was to make the actors react to weight.

Something occupying space.

Something moving vegetation.

Something huge enough that the environment responds when it passes.

That matters in a giant-creature film.

A monster stops feeling gigantic the moment the world around it stops reacting.

Nelson has also talked about the film’s inspirations through the language of classic creature features rather than treating Boiúna like a conventional slasher villain.

The result places Beware Boiúna somewhere between horror, survival thriller and action film—the same combination reflected in its current theatrical genre classifications. 

And the creature itself carries a much older name.

Boiúna comes from Amazonian serpent folklore, commonly associated with a giant snake or river serpent. The movie is not a documentary representation of that folklore, and Friday Night VHS should be careful not to treat every piece of regional mythology as though the film reproduces it literally.

What the film clearly does take is the central image:

A massive serpent.

Water.

Territory.

And people who have gone somewhere they do not control. 

That territorial idea gives the movie a simple dramatic engine.

The characters aren't trying to conquer Boiúna.

They aren't superheroes arriving with a plan for killing a monster.

They're medical workers whose mission suddenly becomes irrelevant once something much larger begins hunting them.

Survival replaces purpose.

The jungle changes from workplace to maze.

Water stops being a route through the environment.

It becomes another place the creature can reach them.

And according to the film’s international synopsis, Boiúna is dangerous both on land and in water. 

That removes one of the easiest comforts in an animal-attack movie.

There is no obvious safe terrain.

The river belongs to her.

The jungle belongs to her.

The humans are simply passing through.

Behind the camera, Nelson directs from a screenplay credited in current Lionsgate-facing theatrical metadata to Alan B. McElroy and Tony Giglio, with Robert Kulzer and Jeremy Bolt producing. Constantin Film and JB Pictures are the principal production companies. 

Some databases additionally credit Nelson on the screenplay, while the current Rotten Tomatoes/Lionsgate-facing metadata lists McElroy and Giglio as screenwriters. Because those credit listings conflict, Friday Night VHS should not state that Nelson wrote the screenplay unless the final on-screen credits or Lionsgate press notes confirm it.

That is exactly the kind of tiny discrepancy worth catching before publication.

The finished film runs 104 minutes and carries an R rating from the Motion Picture Association for bloody violent content, some grisly images, and language. 

Lionsgate opens Beware Boiúna in limited U.S. theaters on October 2, 2026. 

So today, September 12, this belongs firmly under:

COMING SOON.

And because the movie has not opened yet, we should stop precisely where the official campaign stops.

We know why the group enters the Amazon.

We know something ancient wakes up.

We know the creature controls both land and water.

We know the humans are suddenly prey.

Everything after that belongs in the theater.

For now, the warning is enough.

The jungle belongs to her.