10 Eco Horror Movies to Watch for Earth Day

Of all the cautionary lessons that horror imparts, one of the most common warns us never to mess with Mother Nature. Those who are careless or hostile to the environment often meet their demises when Earth retaliates violently in eco-horror movies.

Ecological horror movies explore humankind’s estranged, fractured relationship with the planet, and its characters often find themselves on the defense against nature’s wrath. In celebration of Earth Day, an annual event in support of environmental protection, we’re looking back at some of the best eco-horror movies that remind us to take care of our planet… or else.

Here are ten eco-horror movies to watch this Earth Day.

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The Bay

This found footage movie sees a seaside town under siege from an unknown virulent threat. First comes a gnarly rash, then vomiting, then a violent, disturbing death. Eventually, researchers discover it’s a parasitic ocean isopod that’s mutated to an abnormally large size thanks to a nearby chicken farm’s chemicals getting dumped into the ocean. This isopod is most commonly known as the tongue-eating louse as it enters a fish through its gills, attaches itself to the tongue while cutting off circulation until the tongue falls off, and then acts as the new tongue. It then steals all the nutrients until the fish dies. In The Bay, the isopod gets even more horrific now that it’s invaded land and the town’s residents. How it does so makes for some unforgettable nightmare fuel.

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The Beach House

Two troubled college sweethearts set out for a romantic weekend at the family beach house. It turns into a fight for survival when unexpected guests and the surrounding environment show bizarre signs of a mysterious infection. The Beach House starts slowly with the trippy eco-horror, then dives into the deep end, plunging into the cringe-inducing depths of body horror. While the third act goes hard on slimy transformations, look for one unforgettable moment involving a foot injury and a worm-like creature nestled within the open wound. The Beach House drives home the fact that Mother Nature is tired of the constant abuse and aims to reclaim the Earth from humanity.

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Gaia

A routine surveillance mission in a primordial forest results in two park rangers splitting up once their drone goes offline. Almost immediately, one of the rangers gets caught in a trap and encounters a father and son, Barend (Carel Nel) and Stefan (Alex van Dyk), living a survivalist lifestyle in the forest. The pair thrive on foraging and hunting, and they seem to have their own religion far removed from society. Gabi learns to trust them in their care, especially as she discovers a far greater threat lurking in the area. Directed by Jaco Bouwer and written by Tertius Kapp, Gaia relies heavily on visual storytelling to convey depth and sentiment. There’s an almost abstract quality to the narrative as it slowly unveils the forest’s secrets through dreamlike storytelling. It’s helped by fantastic creature design evocative of The Last of Us.

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Isolation

This Irish horror feature by writer/director Billy O’Brien takes place on a rural farm where a bio-genetics experiment with cows is well underway. When one cow gives birth to a mutated calf, born with parasitic fetuses of her own, the place becomes ground zero for a terrifying bid not only to survive but to prevent the parasitic contagion from getting out into the populace. While the origin of the horror may be man-made, nature always finds a way to adapt and evolve. This small, claustrophobic chiller boasts a strong cast led by Sean Harris (The Green Knight, Possum), Ruth Negga (“Preacher,” World War Z), and The Babadook’s Essie Davis in a minor role. Animal lovers, be warned: don’t expect anything good to happen to these cows. 

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Long Weekend

Arguably the most quintessential eco-horror movie on this list. It follows a suburban couple on a weekend getaway at a remote beach with their dog in tow. Director Colin Eggleston traces the couple’s arrival, signaling a dangerous lack of care for their environment before the horror even begins. That there’s icy tension between them only further exacerbates things. A last-ditch effort to save their relationship becomes an intense onslaught when Mother Nature decides it’s had enough and fights back. Long Weekend creatively incorporates a variety of pissed-off fauna to enact retribution, and it builds to a suitably grim conclusion.

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Phase IV

This is not your average Animals Attack horror movie. The plot follows scientists and a girl trying to stop a horde of desert ants that have developed collective intelligence, thanks to a freak cosmic event, from wiping out humanity. Directed by Saul Bass, an acclaimed graphic artist and title designer for films like Psycho and Cape Fear, and penned by Mayo Simon (Futureworld), Phase IV is far removed from the standard ant-based horror. Instead, it’s a psychedelic trip made with intelligence and gorgeous photography. It’s as bizarre as it is bleak and an unconventional highlight for eco-horror.

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Razorback

Otherwise referred to as “Jaws on Trotters,” this Ozploitation gem merges a gritty outback story in the vein of Mad Max with the Jaws horror blueprint… with a giant razorback boar. Based on Peter Brennan’s novel of the same name, Razorback follows two converging plots: one of a rampaging razorback hog and another involving a missing wildlife reporter who traveled to Australia to investigate a shady pet food factory. Director Russell Mulcahy (Highlander, Resident Evil: Extinction) infuses this eco-horror movie with stunning style and bite. The monstrous beast kills indiscriminately, including children.

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The Ruins

A relaxing summer vacation lounging by the resort pool turns into a harrowing fight for survival when a group embarks on a trip to a remote archeological dig in the jungle. They get trapped atop the Mayan temple by the locals and think the harsh elements are the worst of their problems. That’s before they realize the site harbors a very deadly and cunning evil. Instead of a masked maniac picking off unlucky vacationers, it’s one demented killer plant instead. The seemingly sentient vines pick off the group one by one in often gruesome ways. Sometimes (always), it’s better to leave nature in peace.

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Slugs

Slimy garden slugs become more than a nuisance thanks to Pieces’ director Juan Piquer Simón. Toxic waste renders them carnivorous critters with an insatiable appetite. What’s worse is that they multiply and congregate in mass numbers, making these slugs like oozy land piranhas. In other words, the deaths are gruesome and ultra-gory. It’s bad enough when they devour their victims whole, but the worst kills are reserved for those unlucky enough to eat their eggs unwittingly. Being consumed from the inside out is as revolting and unpleasant as it sounds.

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The Stuff

Are you eating it, or is it eating you? Written and directed by Larry Cohen, The Stuff is a marshmallow Fluff-like substance from the Earth that’s harvested and marketed as a zero calorie treat. It’s the latest food craze. The only problem is that The Stuff happens to be a parasite that turns its consumer into a zombie-like creature. Luckily, saboteur Mo Rutherford (Michael Moriarty) and Chocolate Chip Charlie (Garrett Morris) are hired by the pillars of the ice cream industry to get to the bottom of things. While The Stuff is more interested in critiquing consumerism than environmental woes, the gooey substance’s origins effectively highlight how nature always wins in the end. Consider it an eco-horror movie for city dwellers.