Scary Animals: The 10 Creepiest Animals in the World

Written by AZ Animals Staff
Published: December 24, 2021
Image Credit iStock.com/BrianScantlebury
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Natural selection rarely favors the beautiful. In the cold war that is evolution, a willingness to go extreme is often the best way to find a unique niche within an ecosystem. To some degree, beauty is in the eye of the beholder — a fact demonstrated by the affection many people have for possums or the continued popularity of scorpions and tarantulas as pets. And while that means that there’s no definitive methodology for determining what the creepiest animals are, there’s no shortage of scary animals who manage to distinguish themselves from other species and crawl their way into your nightmares.

Our survey of the creepiest animals takes everything into consideration from which species are traditionally the ugliest to which employ disgusting methods to hunt for prey or evade predators. These 10 creepiest animals are a reminder of the diverse and spine-tingling potential there is hidden among species in the natural world.

#10: Sea Squirt — The Animal With the Most Unnerving Defense Mechanism

This scary animal is capable of disemboweling itself.

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Dogs and possums are just two animals that have developed the habit of playing dead, but no other animal on Earth can fake its demise as dramatically as the Polycarpa mytiligera. As a type of sea squirt, they’re primitive-looking animals shaped like tubes that attach themselves to underwater surfaces and use siphons in their body that filter any food matter that passes through their body without needing to move. But when they find themselves threatened, the Polycarpa mytiligera will tear its siphon and literally push its stomach and other organs from its body. It’s not just for show either.

These sea squirts actually disembowel themselves, an act that turns off most predators thanks to a natural aversion to pursuing already dead prey. These sea squirts can continue to give off the appearance of being dead for up to five days as they wait for the danger to pass and their organs to regenerate. Polycarpa mytiligera isn’t the only species capable of this talent either. Up to half of sea squirt species exhibit familiar defensive strategies.

#9: Flying Snakes — The Snakes With the Creepiest Means of Navigation

A flying snake may be harmless to humans, but it’s still scary.

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Snakes posed such an existential threat to early humans that we had to develop an evolutionary aversion to them, so you can blame that if the very thought of a flying snake gives you a rush of anxiety. The five known species of flying snakes can be found in habitats stretching from Indonesia to India, and their unique skills of aerial navigation have developed to help them survive in the dense and highly vertical rainforest ecosystems they inhabit. The mild venom of these snakes and the shape of their fangs make them harmless to humans, but that doesn’t make their ability to glide accurately for distances of two dozen meters any less disconcerting. A combination of incredibly aerodynamic physiology and an undulating motion that resembles the movement of sea snakes ensures that these serpents never have to leave the trees.

#8: Northern Short-Tailed Shrew — The Cutest Mammal With the Creepiest Hunting Method

The venom the northern short-tailed shrew produces makes it one of the scariest animals.

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There are nearly 400 different shrew species, and most of them are as harmless as the common mouse they most closely resemble. That’s not true of the short-tailed shrew. Because while these small insectivores are too petite to pose any threat to humans, shrews are one of only three types of mammals — alongside bats, platypuses, and slow lorises — that are capable of producing venom.

The northern short-tailed shrew can be found throughout North America‘s northeast regions, and the venom their mouths produce allows them to paralyze animals significantly larger than themselves. Their high metabolisms require them to eat up to three times their body weight in a single day, and that makes prey like mice, other shrews, and salamanders a necessity. Unlike snakes and spiders which employ syringe-like fangs to inject their prey with venom, these shrews have a mouth filled with 32 viciously effective teeth, and they’ll simply sink their teeth into their prey and drool the venom onto them. Often shrews will leave their prey paralyzed but alive for weeks at a time.

#7: Goblin Shark — The Most Ghoulish Shark in the Ocean

The goblin shark is scary given its size of over 12 feet.

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The goblin shark is the sole known member of a taxonomic family that dates back 125 million years ago, and you can count yourself grateful that they live in the ocean at depths of over 2,000 feet. They can reach lengths of over 12 feet and can weigh as much as a quarter ton. Though rarely spotted by humans, their habitats stretch from the coast of Japan to the Gulf of Mexico — and the disturbingly long snout that extends over their ghoulish and exposed jaws seem to have developed as a hunting mechanism for their unique ecosystem. The bizarrely overextended shape of the nose helps them both forage in crevices and more accurately detect the electrical fields of potential prey. It also allows them to open that rictus grin by 110 degrees, allowing them to pursue large prey like squid and other sharks.

#6: Blobfish — The Ugliest Fish in the Water

The blobfish has been carrying the title of ugliest animal in the world since 2013, but their strange, gelatinous physiology is just a reflection of how they’ve adapted to suit an environment that’s entirely alien to us. Found in depths of 2,000 to 4,000 feet off the coast of Australia, the blobfish has developed a body with no underlying skeleton and a jelly-like musculature that allows them to survive at such deep pressures. That results in a bulbous and distended face with disturbingly human characteristics when taken outside of the water. But in deeper waters, the higher pressure gives them form and structure that the oxygen above can’t, and they resemble any number of other fish species in their natural habitat. Blobfish merely wander aimlessly through their deepwater habitats and devour whatever food comes their way — but they’re a good reminder that what may seem hideous to us is merely par for the course for survival in the ocean.

#5: Shoebill Stork — The World’s Scariest Bird Species

The creepy shoebill stork seemingly poses no threat to humans.

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Shoebills pose no threat at all to humans and have been known to let researchers get mere feet away from them comfortably, but the bizarre shoe-shaped beak attached to their face is still a terrifying weapon in the wild — and that’s earned this avian a position as the creepiest bird on Earth. Size has a big part to play in this. Shoebills may be gangly, but they can reach a height of five feet and a wingspan of roughly seven feet. That size allows them to hunt down large prey like catfish, eels, and even baby crocodiles as a matter of course. But it’s their method of hunting that’s the scariest thing about them.

These storks will fall headfirst with their beaks open to trap live prey whole. The stork will then open its mouth slightly and decapitate them with its razor-sharp beak when they try to escape. These birds are even known to fight fully grown crocodiles, and their mating call sounds alarmingly like a machine gun.

#4: Aye Aye — The Creepiest Animals That Are Harmless

In Malaysia, the aye-aye is considered to be bad luck.

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A resident of Madagascar, the aye-aye is easily the most unusual looking lemur in the world — but while some people find these primates to fall into the category of animals that are so ugly that they’re cute, that’s not an impression that’s generally shared by the locals who share a habitat with the aye-aye.

As nocturnal and elusive creatures, their wild eyes and demonic features can make them look positively terrifying on sight, and many Malaysian communities kill aye-ayes on sight out of a belief that they’re a harbinger of bad luck or that they use their bony and ghoulish middle fingers to pierce the hearts of humans in their sleep. The truth is that these fingers actually developed as a way of finding grubs and other invertebrate prey hiding in trees through echolocation. Despite ranking near the top of the list of animals that are harmless, they’re highly endangered thanks to these superstitions and to commercial deforestation.

#3: Goliath Bird-Eating Tarantula — The Largest and Creepiest Spider

This scary animal injects its prey with a juice that liquefies all but the skin and bones.

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The long-dead megarachne was a spider capable of reaching a length of nearly two feet – but if you remove spiders that are extinct from the equation, the biggest and scariest arachnid on the record is likely the Goliath bird-eating spider. The Goliath tarantula is known to reach a width of nearly one foot, but its size isn’t the only intimidating thing about it. The inch-long fangs make a pretty persuasive argument for many predators to stay away, and the Goliath tarantula is covered in sharp and bristled hairs that can be rubbed together to make a hissing noise or flung like quills at any threatening animals.

Despite its name, birds are actually a rare part of this spider’s diet. But those that do get caught are in for a horrifying fate. After disabling prey with neurotoxins, this tarantula will inject their prey with digestive juices which then liquify everything but the animal’s skin and bones.

#2: Coconut Crab — The Scariest Crab Species on Land

The coconut crab is a scary animal that sometimes eats each other.

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As if a bird-eating spider wasn’t scary enough, meet the crab capable of doing the same. They’ve been known to feast on rats, domesticated chickens, and even kittens. They’ve also been known to cannibalize one another with little hesitation. These are the largest land crabs on Earth with a width of three feet and a length of a foot and a half — and their overgrown claws are known to be capable of exerting pressure that can rival the bite force of bears and cheetahs. They often use these claws to tear at the flesh of any prey they can find, but this crab’s exceptional exertion is primarily used to crack open coconuts in their Pacific island habitats. Their well-documented habits for being voracious eaters have even led to a compelling theory: that they were responsible for the disappearance of Amelia Earhart’s body and that they might have even devoured her while alive.

#1: Arthropleura — The Scariest Animals That Are Extinct

The arthropleura, now extinct, was once able to grow larger than eight feet.

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If the alien features and multitudinous legs of a millipede or centipede aren’t enough to give you nightmares, meet the Arthropleura — and be lucky that these are one of the many megafauna species that are extinct. Their shape would be familiar to anyone who’s encountered a millipede, but it’s their size that really makes them such apparently scary animals. The Arthropleura was capable of reaching a length of over eight feet. That makes them the largest invertebrates on record, and it was once believed that they were voracious and wandering predators. But more recent research indicates these rank among creatures that are harmless despite looking frightening.

Ultimately, changes in the environment led to the downfall of this massive invertebrate. High concentrations of oxygen in the Earth’s atmosphere and a distinct lack of large predators allowed Arthropleura to thrive for a time, but this millipede’s unique physiology eventually became unsustainable.

While none of them can match Arthropleura in size, you can learn about the five largest millipedes still alive here.

Based on our research, here are the ten creepiest animals in the world:

Next up: Mongoose vs Snake: Who Would Win in a Fight?

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AZ Animals is a growing team of animals experts, researchers, farmers, conservationists, writers, editors, and -- of course -- pet owners who have come together to help you better understand the animal kingdom and how we interact.

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