It would not surprise us if we saw a new wave of ecological horror in which our own mistreatment of the environment and our irresponsible handling of pharmaceutical progress creates flesh hungry critters, pissed off two-headed bears, opioid addicted tapeworms, whatever. Let’s prepare by looking over history’s forewarnings, shall we?

Here are our favorite mutant animal films—cautionary tales about big pharma, careless planet keeping and sex.

5. Shivers (They Came from Within) (1975)

In an upscale Montreal high rise, an epidemic is breaking out. A scientist has created an aphrodisiac in the form of a big, nasty slug. That slug, though, spreads wantonness throughout the high rise and threatens to overrun the city with its lusty ways.

Not Cronenberg’s best film, but this is his first feature length horror and it announces not only his arrival on the genre scene, but it predicts so many of the films to come. The film obsesses over human sexuality, social mores, the physical form, physical violation and infestation, medical science, conspiracy, and free will. He’d revisit all of these preoccupations throughout his career, most obviously in his very next feature film, 1978’s Rabid, which is weirdly similar in every way.

Shivers takes a zombie concept and uses it to pervert expectations. (See what we did there?) They’re not here to eat your brains, after all. It’s the first film where Cronenberg marries ideas of the repugnant with the pleasurable, medical monstrosity with human body. It would be several years before his skill with performances (or maybe casting) matched his other directorial talents, but Shivers is still a worthwhile, utterly bizarre pleasure.

4. Isolation (2005)

In 2016, writer/director/Irishman Billy O’Brien made an effective and lovely – yes, lovely – creature feature called I Am Not a Serial Killer. But about a decade earlier, he started down that path along a muddy, ruddy Irish roadside that wound ‘round to an out-of-the-way farm.

It’s the kind of a depressing, run-down spot that would catch nobody’s eye – which is exactly why it drew the attention of runaway lovers Jamie (Sean Harris) and Mary (a young Ruth Negga – wonderful as always). The solitude and remoteness also got noticed by a bio-genetics firm.

Down-on-his-luck Farmer Dan (John Lynch, melancholy perfection) has little choice but to allow some experimentation on his cows. He doesn’t really mind the required visits by veterinarian Orla (Essie Davis – hooray!).

But when one cow needs help delivering – genetic mutations, fetuses inside fetuses and teeth where no teeth belong. Nasty.

O’Brien and his truly outstanding cast create an oppressive, creepy, squeamish nightmare worth seeking out.

3. Black Sheep (2006)

Graphic and gory horror comedy seems to be the Kiwi trademark, no doubt a product of the popularity of native Lord of the Gastro-Intestinal-Splatter-Fest-Laugh-Riot, Peter Jackson.

First-time writer/director Jonathan King uses the isolation of a New Zealand sheep farm and the greedy evil of pharmaceutical research to create horror. He does it with a lot of humor and buckets full of blood. It works pretty well.

Evil brother Angus (Peter Feeney) has bred some genetically superior sheep while smart but sheep-phobic brother Harry (Nathan Meister) has been away. But the new sheep bite (a recurring problem with bio-genetically altered farm animals). Victims turn into, well, were-sheep. Of course they do.

The result is an endearing, often genuinely funny film. Cleverly written with performances strong enough to elevate it further, Black Sheep offers an enjoyable way to watch a would-be lamb chop get its revenge.

2. The Host (2006)
Visionary director Joon-ho Bong’s film opens in a military lab hospital in 2000. A clearly insane American doctor, repulsed by the dust coating formaldehyde bottles, orders a Korean subordinate to empty it all into the sink. Soon the contents of hundreds of bottles of formaldehyde find its way through the Korean sewer system and into the Han River. This event – allegedly based on fact – eventually leads, not surprisingly, to some pretty gamey drinking water. And also a 25 foot cross between Alien and a giant squid.

Said monster – let’s call him Steve Buscemi (the beast’s actual on-set nickname) – exits the river one bright afternoon in 2006 to run amuck in a very impressive outdoor-chaos-and-bloodshed scene. A dimwitted foodstand clerk witnesses his daughter’s abduction by the beast, and the stage is set.

What follows, rather than a military attack on a marauding Steve Buscemi, is actually one small, unhappy, bickering family’s quest to find and save the little girl. Their journey takes them to poorly organized quarantines, botched security check points, misguided military/Red Cross posts, and through Seoul’s sewer system, all leading to a climactic battle even more impressive than the earlier scene of afternoon chaos.

1. The Fly (1986)

After a couple of interesting, if un-medical films, the great David Cronenberg made a triumphant return to the laboratory of the mad scientist in his most popular film to date.

But it’s not just Cronenberg’s disturbed genius for images and ideas that makes The Fly fly; it’s the performance he draws from Jeff Goldblum.

Goldblum is an absolute gift to this film, so endearing in his pre-Brundlefly nerdiness. He’s the picture’s heartbeat, and it’s more than the fact that we like his character so much. The actor also performs heroically under all those prosthetics.

He and Geena Davis make the perfect pair, with their matching height and mullets, and their onscreen chemistry does give the film a level of human drama traditionally lacking from the Cronenberg canon. Atop that, there’s the transformation scene in the bathroom – the fingernails, the pustules – all classic Cronenberg grotesquerie, and still difficult to watch.

https://www.youtube.com/watch?v=7BzwxJ-M_M0