In truth eco-horror, or ecological horror, is a vague amalgamation of horror media somehow related to ecological or environmental topics. It is a wide umbrella adjacent to other iconic monuments of horror: the zombie, monster, and alien subgenres. Depending who you ask, eco-horror even borderlines sci fi horror (it is ultimately a matter of where the Thing comes from, no pun intended). Lovecraft’s The Colour Out of Space is a great example of a horror story that is labeled “sci fi” because the horrific “being” comes from outside of Earth. But that’s as far as the short story goes into sci fi terrain. After a careful read, you’ll notice how much emphasis Lovecraft puts on the detrimental effects that the color had on the land and the living things that inhabit(ed) it. The color is a force of nature that blights the land because that’s what it does. For its themes, The Colour Out of Space is undeniably a tale of eco-horror.

In a way, eco-horror is a rebranding of horror subgenres that focus on the impacts of human life on the environment, on mutated life forms that are the product of scientific greed, and on dark secrets found deep within nature, better left untouched. Eco-horror is held together by themes rather than narrative elements, character stereotypes, or visual conventions, which makes it hard to distinguish from more traditional subgenres. This is evident as the best examples of eco-horror are also iconic representatives of other horror subgenres. Think of Bong Joon-ho’s The Host (2006), a staple of monster films. Look no further beyond John Carpenter’s The Thing (1982) or Ridley’s Scott’s Alien (1979), both sci-fi horror classics. Even the criminally underrated The Bay (2012) is just shelved as a horror mockumentary.

While eco-horror films inevitably bleed into other categorizations of horror media, it’s worth peeking at this subgenre through the transparent, sterile test tube it is contained in. After all, aren’t we living our own nature-gone-bad pandemic?

Here There Be Monsters: The Gnawing Hunt

Puritans of this hidden subgenre would point to 1954’s Them! as one of the best examples of, if not the first, eco-horror film. Them! narrates the catastrophic events after nuclear fallout mutates a colony of ants into gigantic human-devouring monsters. I personally wouldn’t consider Them! as part of eco-horror since the nuclear theme is not central to the story. But still, many of eco-horror’s monster films are heavily rooted in Them! 

Them!’s influence is undeniable. Firstly because it showed that there is violence in nature. This is a violence devoid of malice, fueled by the need to consume. It stands against the idea that “natural” is intrinsically good. In eco-horror, nature isn’t good. But it’s not evil either; it just is. The idea that our fictional demise is part of some natural order is quite dreadful. It has a pinch of Lovecraft’s cosmic horror but flipped inside out. 

Secondly, Them! showed how science and human experiments can lead to the unnatural and dangerous, to the creation of monsters. Literal ones. If that statement gave you Frankenstein; or, The Modern Prometheus vibes, you’re starting to get it. Like in Mary Shelley’s icon novel, eco-horror starts with an abomination. Just swap out philosophy on human nature for biology on nature’s nature.

Defining the Monster: What is Evil?

In eco-horror that features monsters, the monsters are not the true source of suffering, even when they cause destruction. This is evident in the critically acclaimed The Host, a widely popular film about a huge amphibious monster that grows from dumping toxic waste into a river. The movie is not really about the perilous creature. It’s a story with strong environmental undertones, condemning ecological misconduct in the use of chemicals and toxic waste disposal. The monster is a manifestation of biological terror, and the fact that the film is heavily inspired by real events just lands a stronger impact. 

Do you know what else is inspired in real events? The Bay, a found footage film about a bacterial outbreak resulting from the manmade pollution of the Chesapeake Bay. The story is interesting because it zig-zags between fiction and reality. It has enough scientific foundations to feel believable and enough liberties to turn the real horrific. Do you notice a trend here? Like The Host, The Bay touches on the systematic, large-scale pollution of water bodies and how easily life will adapt to the changing environment, screwing humans up in the process. We are no strangers to epidemics. We know how easy tiny organisms can turn the world upside down despite our efforts to prove we are the intelligent ones out here. That’s a core element of eco-horror and it’s chilling to the bone. Nature will survive, with or without humans.

There Is Horror Under the Leaves: Forbidden Wilds

Horror is not always created from nature. Horror can also be found in nature, sprouting from the amoral chaos of evolution and survival. This is commonly explored through the idea that some corners of the natural world are not meant for humans to explore. This is honestly my favorite kind of eco-horror because it finds horror in the environment itself. 

One of the most recent additions to the subgenre is a small South African production that came out in 2021 titled Gaia. It’s a fascinating tale about a forest ranger that stumbles upon a father and son that live as survivalists deep inside the forest. Gabi, the protagonist of the film, soon discovers that the two strangers are part of something dark involving fungi and an offering tree. With stunning practical effects that are no longer seen these days, Gaia is a puzzling examination of our relationship with the planet. While it struggles to fully come together in what it’s trying to say, Gaia delivers an atmospheric experience that reevaluates our place in a complex, changing ecosystem. 

American writer Dan Simmons touches on similar ideas in his 1989 novel Hyperion. The book starts with the tale of Paul Duré, an exiled priest who documents his search for a native civilization known as the Biruka. To find this long-forgotten tribe, he must first cross a deadly forest of trees that discharge lightning bolts. Tesla trees are not the only natural terror that he encounters as he comes to realize the troubling truth connected to the seemingly immortal Biruka. 

There’s a symbiotic relationship that seems malignant in our understanding of what life is. It’s gruesome and it’s bloody. It horrifies Paul Duré and us, the reader. And existing beyond the immediate flight-or-flight threat are the peaceful Biruka. Humanoid in appearance and fully at peace with the relationship they have formed with their habitat. The contrast between two closely related species, us humans and the Biruka, having opposite reactions to the same biological phenomenon is very powerful and effective.

I want to finish this with a note on Annihilation, a 2014 film adaptation of Jeff Vander Meer’s novel of the same name. The story centers on a group of female scientists that make an expedition into a biologically mutated zone called The Shimmer. The zone is a crash site of a meteorite and everything inside it seems to be off. Most notably, it is expanding in size. As the group goes deeper into The Shimmer they observe that life becomes progressively more altered. Lena, the protagonist, finds flowers that appear stuck in “continuous mutation”, animal species that have impossibly cross-bred, and frozen trees that grow out of the sand. 

The story is deeply psychological; the eco-horror elements enhance the bizarre, twisted atmosphere of the story. Ultimately, our perception of our environment, however arable or threatening it might be, reflects our perception of humankind, of our place in that environment. In the face of all the unstoppable change, a character tells Lena that The Shimmer is destroying everything. She replies, encapsulating the core of eco-horror sentiment:

It’s not destroying. It’s making something new.