The shark remains the reigning champ of aquatic horror, dominating the subgenre more than any other oceanic creature. Alligators, crocodiles, and mutated fish make up another large percentage of an already shallow pool. Then there’s cryptids and sea creatures, of which horror always has room for more. That includes the folkloric creature made benign and romantic by Disney, the mermaid.

Folktales of sea-dwelling humans with fish tales date as far back as ancient Assyria, with the goddess Atargatis. Mermaid legends spread over time and across cultures, while the Western iteration is often considered to draw from Greek mythology’s Sirens. These bird-like creatures lured sailors to their deaths through enchanting song. Sometimes the mermaid signals impending doom, and other tales depict the being as a sign of good luck. Stories of mermaids luring sailors became so prominent that it bled into history; a 1493 log entry in Christopher Columbus’s journal detailed seeing three mermaids in the Caribbean Sea. The common belief is that the explorer mistook manatees for mermaids, but there’s no way to conclude what he saw definitively. 

All of which to say that the entity is so culturally ingrained yet loosely defined enough that it’s not surprising at all that the mermaid eventually invaded cinema. While most of the mermaid’s appearances play on romance, leave it to horror to lean into the darker nature of the mythology. The sea creatures’ first foray in genre film belongs to 1961’s Night Tide, a psychological horror thriller centered around a romance, written and directed by Curtis Harrington. 

‘Night Tide’

Dennis Hopper starred as Johnny Drake, a sailor on leave in California. He meets and falls for a woman named Mora (Linda Lawson), who performs as a mermaid in a sideshow attraction at the pier. It’s operated by the man who found her orphaned on an island as a child, Captain Murdock (Gavin Muir). The more Johnny gets romantically involved with Mora, the more he begins to suspect she may not just be pretending to be a mermaid; she may be one.

Strange behavior and a history of boyfriends that died under mysterious circumstances add to the mounting evidence. While the folklore plays heavily into the plot, the truth paints a more bleak picture. In many ways, Mora speaks to the myth of the sea creatures as harbingers of doom; but injected with a hefty dose of realism.

‘She Creature’

Horror took its next significant swing at the creature in 2001, with the Stan Winston produced She Creature. First in a series of made-for-TV movies for Cinemax, and initially titled Mermaid Chronicles Part 1: She Creature, writer/director Sebastian Gutierrez paid tribute to 1956’s She-Creature in name only.

In 1905 Ireland, carnies Angus Shaw (Rufus Sewell), and his wife Lillian (Carla Gugino) encounter a man claiming to have an actual mermaid in his possession. After an incident gone wrong, Angus and colleagues abduct the mermaid with plans to bring her across the sea to America. Their voyage reveals a much darker side to the mermaid. Thanks to some excellent special effects and creature design by Stan Winston Studios, the mermaid gets downright monstrous in an exciting way. Perhaps for the first time.

‘Dagon’

Hot on She Creature’s heels came the release of Dagon, a Stuart Gordon-helmed loose adaptation of H. P. Lovecraft’s novella The Shadow Over Innsmouth. While the eponymous sea god spawned all manner of half-human, half-creature offspring, its most prominent in the narrative is that of Uxía (Macarena Gomez). She’s a beautiful mermaid that haunts the lead’s dreams until he discovers she’s real after washing ashore in a strange town. Instead of a fish tail, though, it’s more octopus-like.

Much like She Creature, this mermaid is a siren call to damnation.

‘Cabin in the Woods’

The Cabin in the Woods used the merman to comedic effect without sacrificing the horror.

Five college friends head out to a remote cabin for the weekend, unaware that they’re manipulated into playing a role in an elaborate ritual by an underground facility. They unwittingly choose the method of their intended deaths via the “Zombie Redneck Torture Family,” but the facility holds hundreds of monsters at their disposal. The running gag is that Steve Hadley (Bradley Whitford) has longed to see the Merman monster in action until he finally gets his wish in the third act. A merman finds Steve, devours him, then expels the leftovers through its blowhole.

‘The Lure’

Then came two back-to-back mermaid features from Europe in the mid-2010s, both getting primal with the folklore and using it as a coming-of-age metaphor.

In 2015’s The Lure, Agnieszka Smoczyńska brought this ’80s cabaret set adaptation of “The Little Mermaid” back to its darker, bloodier roots. Mermaid sisters Silver (Marta Mazurek) and Golden (Michalina Olszańska) come ashore in Warsaw and get adopted by a nightclub band. Silver falls in love while Golden explores the pleasures of humanity, including dining on their flesh. While movies have long favored the attractive, romantic version of the mermaid over the horrific, Smoczyńska offers both.

‘Blue My Mind’

Similarly, 2017’s Blue My Mind saw a young teen struggle with the overwhelming onslaught of puberty both emotionally and physically. Lisa Brühlmann‘s feature debut followed Mia’s (Luna Wedler) attempt to navigate the murky waters of high school hierarchy while coping with alarming body changes. The more Mia’s body reacts and transforms in inhuman ways, the more she begins to suspect she may be adopted. It’s a mermaid body horror movie by way of coming-of-age drama. 

Robert Eggers quickly established himself as a filmmaker who gets extensive on his research to ensure period accuracy after debuting The Witch. His follow-up continued that reputation. The Lighthouse played like a stylistic sea shanty turned hallucinogenic mind trip, in which two lighthouse keepers go stark raving mad while on an isolated island. Both Winslow (Robert Pattinson) and Wake (Willem Dafoe) experience visions of a mermaid, an attractive yet terrifying creature. Eggers spared no detail, even studying the anatomy of marine life, notably sharks, to ensure precision for the mermaid’s genitalia.

‘Monsterland’

Last year’s Monsterland series on Hulu, based on North American Lake Monsters: Stories by Nathan Ballingrud, featured a Texas-based episode about a fisherman and his prized mermaid captive. “Palacios, TX,” directed by Nicolas Pesce, brought a carnivorous iteration of the myth to the small screen. Using the story thread that some mermaids grant wishes in exchange for freedom, Pesce toys with ambiguity; is what’s happening accurate or all in the fisherman’s head? It makes a modern complement to Night Gallery’s season two episode “Lindemann’s Catch,” which also features a sea captain obsessed with a mermaid catch.

Mermaids make up a tiny fraction of the aquatic sub-genre; they’re far more commonly found as curious romantic leads in comedies or fantasy fare. Their most memorable appearances in horror often belong to the mermaids that bring total body transformations, like the repulsive merman from The Cabin in the Woods or the shapeshifting mermaid in She Creature. It’s probably why their more monstrous relatives, aquatic humanoids in films like Creature from the Black Lagoon or Humanoids from the Deep, instill fear straightaway without the pretense of romance (though they try). But horror can always use more human-devouring mermaids and creature-filled aquatic horror.