5 Real-Life Monsters to Fuel Your Nightmares

Monsters aren't just the stuff of Hollywood horror movies. Here are five "creeptacular" examples of monsters living among us.

Sabrina Stierwalt, PhD
6-minute read
Episode #349

I love anything spooky, whether it’s suspenseful tension, over-the-top gore, or just plain disconcerting creepiness. And apparently I’m not the only one. Horror movies are quickly gaining in popularity. In 2017, the horror genre grossed more than $1 billion in ticket sales for the first time ever.

Some say it’s our inner bad guy that draws us to horror. Others say it’s being able to experience the thrill of danger while knowing we're in the safe confines of a movie theater or our living room.

But what happens when these creepy crawlies and things that go bump in the night aren’t just a part of our silver screen imaginations? Let’s investigate some real life monsters. I'll leave you to decide whether they're totally cool or nightmare fuel.

Giant squid 

Release the kraken! Let’s start off with one of my biggest fears: giant squid.

Giant squid have always deeply freaked me out. They can grow as big as 45 feet long (at least the females can), and they have eyes the size of dinner plates. They can snatch you from as far as 33 feet away by shooting out one of their feeding tentacles. If that’s not creepy, I don’t know what is. 

They can snatch you from as far as 33 feet away by shooting out one of their feeding tentacles.

You might consider this a silly thing to be afraid of. Krakens—I mean, giant squid—are typically only found at ocean depths below 1,000 feet (that’s about 300 meters). But I once saw a documentary that claimed giant squid were “more common than you think.” Now, I hear that phrase whenever my logical brain tries to convince me that I will very likely never ever in my life encounter a giant squid. 

Exaggerated versions of a giant tentacled sea monster known as the kraken have long appeared in Scandinavian folklore, possibly based on sightings of actual giant squid. They’ve also wreaked havoc in movies. The god Zeus in Clash of the Titans called upon one as he famously yelled, “Release the kraken!” Davy Jones called on a giant squid to destroy the ships of his adversaries in Pirates of the Caribbean. Of course, a real-life giant squid wouldn't be able to sink a ship, so you're probably safe on your next all-inclusive ocean cruise.

So, how common are they? A giant squid would be hard to miss if you encountered one. Wikipedia even has a page that claims 600 sightings from the 21st Century alone! But the ocean is large and giant squid lurk well below the surface.

Marine biologists can make a rough estimate of the number of giant squid in existence based on the number of squid beaks they find in the bellies of sperm whales, the giant squid’s main predator. Those parrot-like beaks are hard to break down and usually don’t get fully digested. This gruesome evidence suggests there may be more than 4 million of the giant sea creatures.

If you want to see a giant squid for yourself, the Smithsonian’s National Museum of Natural History has two on display. The larger one, the female, was caught off the coast of Spain and was likely 36 feet long when alive. She was transported to the museum in Washington, D.C. from Spain by the United States Navy and Air Force via an effort called, of course, Operation Calamari

Vampire bats

From the strigoi of Romania to the Chupacabra of Puerto Rico, creatures that feed off the blood of their victims are a cross-cultural legend. But are nocturnal, fanged blood-suckers only the stuff of movies? 

Their noses act like heat sensors, helping them find precisely where the blood is pumping beneath the skin of the animal that hosts their next meal.

In some vampire stories, the immortal creatures can take both human and bat form. Bats already stick out as oddballs in the animal kingdom: they sleep upside down in dark, damp caves during the daytime and are the only mammals that can fly. But some types of bat also represent the only species that feed entirely on the blood of other animals. Their noses act like heat sensors, helping them find precisely where the blood is pumping beneath the skin of the animal that hosts their next meal. These bats are officially called vampire bats and come in the common, hairy-legged, and white-winged varieties. 

Despite their fierce-sounding name though, common vampire bats are actually quite cute. They're only about the size of a teacup and weigh around 2 ounces, a weight that they can double in just a single feeding. They don’t drink enough to harm their victims, either. But their bites can cause infections, which can be lethal. Vampire bats like to live in large groups called colonies of anywhere from 100 to 1000 bats. In a year, a colony of 100 bats will consume the blood of around 25 cows. 

Just a few weeks before Halloween, five purebred bulls were found entirely drained of their blood on a ranch in eastern Oregon. But the culprit doesn’t appear to be a vampire bat colony. For starters, vampire bats are usually found in Mexico, Central, and South America. And also, the bulls’ tongues had been surgically cut out.

Zombie snails and ants

Originally from Haitian folklore, the idea of the undead feeding on the brains of the living has been a very popular topic for horror movie fans for decades. We like to argue whether zombies would be fast- or slow-moving, and how exactly such a zombie virus would spread. Scientists have even built models to figure out where you’d have the best chance of surviving a zombie apocalypse. (Hint: I’ll meet you in Colorado.) 

But we also see real-life zombies thanks to parasitic worms and fungi that coopt the brains and/or bodies of larger species like snails and ants and then force their host to behave in ways that are advantageous to the parasite but not to the snail or ant.

The zombie ant fungus known as cordyceps compels its host ant to leave its colony and position itself in a plant overhead. The fungus then forms a fast-growing stalk that forces its way up and out through the ant’s head so it can rain down spores on the ant colony below, proof that nature can be really creepy.

There have also been zombie snails. These snails are infected by worms that make the snail’s antennae look like maggots or caterpillars. The parasitic worm’s goal is to make the snail look like a yummy snack for birds flying overhead. When a bird eats the infected snail, the parasite now has a bigger host. The worm multiplies in the bird's stomach, is excreted through droppings, and then consumed by more snails. That's the circle of life taken to a whole new creeptastic level.

Paris Blob

In the 1950s, a jello-like, intelligent alien life form tried to take over a small town in Pennsylvania in the sci-fi movie classic The Blob. And just a few weeks ago, representatives of the Paris Zoo announced that they are now home to a yellowish, single-celled creature that can move without legs and has no mouth, stomach, or eyes. This blob can heal itself within two minutes of being cut in half. Scientists studying the organism say they don’t really know if it’s an animal or a fungus, although some sources refer to it as a species of slime mold. It looks like a mushroom, but it's capable of learning and transferring its knowledge to other blobs as an animal would.

Goliath spiders 

And in case you weren’t already reaching for a nightlight to drive away the monsters, let’s not forget the classic dark comedy horror movie, Arachnophobia. In the movie, small-town America was threatened by aggressive killer spiders from the Venezuelan rain forest.

They weigh up to 175 grams, which is around the weight of a billiard ball.

The spider in the movie was fictional, but the largest spider (by mass and size) is called the Goliath birdeater. It's found in the Venezuelan rainforest. The Goliath spiders can have bodies as long as 12 centimeters (just over 4.5 inches) and extend as long as 1 foot (or 30 centimeters) when you include their legs. They weigh up to 175 grams, which is around the weight of a billiard ball. Despite their name, however, they mostly prefer to eat worms and amphibians over birds. 

What real-life monsters have you encountered?


Dr. Sabrina Stierwalt is an extragalactic astrophysicist at the California Institute of Technology and Adjunct Faculty at the University of Virginia. Stay in the science loop! Listen and subscribe to the Ask Science show on Apple, Spotify, or wherever you get your podcasts.

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About the Author

Sabrina Stierwalt, PhD

Dr Sabrina Stierwalt earned a Ph.D. in Astronomy & Astrophysics from Cornell University and is now a Professor of Physics at Occidental College.