Top 10 Creepiest Underwater Creatures That Actually Exist



Top 10 Creepiest Underwater Creatures That Actually Exist

VOICE OVER: Rebecca Brayton WRITTEN BY: Garrett Alden
These creepy creatures will make you rethink your next scuba diving trip. For this list, we'll be looking at aquatic creatures whose appearance, behavior, and other attributes make them extra spooky. Our countdown includes Giant Squid, Atolla Jellyfish, Vampire Squid, and more!

Top 10 Creepiest Underwater Creatures

Welcome to WatchMojo, and today we’ll be counting down our picks for the top 10 creepiest underwater creatures.

For this list, we’ll be looking at aquatic creatures whose appearance, behavior, and other attributes make them extra spooky. We’ll be excluding fish though, as those already have a list of their own.

Which one gives YOU the heebie jeebies? Tell us in the comments!

#10: Giant Squid

We figured we’d get the obvious one out of the way. Although giant squids have long been the subject of legends about undersea monsters, it wasn’t until the early 2000s that the creatures were actually photographed on camera. With lengths that can reach between 45 and 59 feet, giant squids are some of the biggest living animals. They’re large enough to give certain whales a run for their money! Their enormous size and many tentacles have fascinated and frightened people for centuries. Giant squids have such a legendary and intimidating reputation that we’re scared what they’d do if we left them off our list.

#9: Giant Isopod

Giant isopods are a creepy crawly type of crustacean that live deep within most of the world’s major oceans. If they look like giant pale pill bugs to you, there’s a good reason – they’re actually related to the insect. However, giant isopods are much more than your average roly-poly. These aquatic creatures are opportunistic scavengers that are willing to eat dead organisms they come across as well as other living animals. Their compound eyes and seven pairs of wiggly legs are much less cute than their terrestrial counterparts. And did we mention the larger ones can be over a foot long?

#8: Atolla Jellyfish

Jellyfish in general are already pretty creepy. Unfortunately, they only get spookier as you dive deeper into the ocean. The Atolla jellyfish inhabit the midwater section of the sea. These creatures bear a rich red color that makes them look like bloody, tentacled brains. As if that weren’t creepy enough, they’re also bioluminescent; meaning they produce their own light. They can use their bioluminescence for a terrifying defense. If threatened, the Atolla jellyfish may flash their inner light to attract something more dangerous than the predator that’s attacking it. Their appearance and bioluminescence make them resemble tiny underwater UFOs. Since we don’t want to be abducted, we’re gonna stay away from these jellyfish.

#7: King Crab

Seafood enthusiasts may eat king crab with gusto, but seeing these crustaceans while they’re alive is enough to dampen anyone’s appetite! Part of why they’re so sought after is their size. The bigger they are, the more meat they can produce. While it can vary by species, the red king crab is the largest of the bunch. Their legs can grow to a span of over 5 feet! These wide creatures are also adorned with spines on their tough shells that both protect them and make them absolutely terrifying. King crab may be tasty, but we’ll leave their capture to braver souls than us.

#6: Ausubel's Mighty Clawed Lobster

Dinochelus ausubeli, A.K.A. Ausubel’s mighty clawed lobster, A.K.A. the terrible claw lobster, is a species of lobster that was first discovered in 2007. The creature was first located in the deep sea off the coast of the Philippines. Although the terrible claw lobster may only be around an inch long, its appearance is still plenty creepy. The creatures have a semi-translucent exoskeleton that has pink and orange highlights. The tiny lobster also has two claws with serrated “teeth”. To top it all off, one of its claws is typically significantly longer than the other. While we know it’s small, we can’t help but imagine how terrifying this lobster would be if it were larger.

#5: Sea Spiders

Did you need another reason to be afraid to go in the water? Well, we’ve got you covered. Despite their name, sea spiders aren’t technically spiders. But although they’re arthropods instead of arachnids, you’ll definitely want to steer clear of them if long legs aren’t your thing. These creatures are practically all legs. Unlike actual spiders, some species can have up to 10 or 12 legs in total. Their sizes can also vary wildly between species. The most terrifying sea spiders can grow legs that are over 2 feet long! And just in case you were hoping they were confined to one area, they’ve been found in oceans across the globe. Terrific.

#4: Flying Spaghetti Monster

Praise the flying...wait, we’re not talking about the deity? As it turns out, flying spaghetti monsters are technically a real thing. When this marine creature was discovered, it was given the scientific name Bathyphysa conifera. But it didn’t take long for people to start calling the animal a flying spaghetti monster. These creatures look like an elongated, inside-out jellyfish made of pasta. And each one is actually a colonial organism made up of many smaller animals known as zooids. Basically, it’s a tentacled monster that typically measures over a meter long and is made up of tinier creatures. The creature’s design and characteristics still make us wonder if they’re native to Earth, or if they’re really Cthulhu’s spawn.

#3: Colossal Squid

While they may not get as long as giant squids, colossal squids have their fellow giant squids beat in weight class. Certain specimens have been known to weigh over half a ton! The hooks that these massive cephalopods sport on their arms and tentacles are probably incredibly painful to any whales that try to feed on them. When it comes to catching their own prey, colossal squids use their bioluminescence to bring their food to them. Since they primarily inhabit the deep oceans closer to the south pole, their interactions with humans have been fairly limited. But we’d frankly rather know more about an animal this frightening.

#2: Vampire Squid

The scientific name for this creature is Vampyroteuthis infernalis, which translates to vampire squid from hell. Unfortunately, this creature definitely tries to live up to one of the scariest names in the animal kingdom. Named for its webbed tentacles and its tendency to have reddish features, the vampire squid is actually more of a zombie scavenger than a blood-sucker. They tend to feed on waste and animal remains. The most disturbing thing about this creature is its primary defense mechanism. It’s capable of turning itself inside out and using the spines that line the bottom of its webbed tentacles to injure predators. While it’s not as big as other cephalopods on our list, it may be the most frightening of the bunch!

Before we get to our top pick, here are a few honorable mentions:

Big Red Jellyfish
A Meter Wide Monster with “Feeding Tentacles”

Crystal Jelly
These Transparent Jellyfish Can Glow in the Dark!

Holothurians [aka Sea Cucumbers]
Those Colorful Tentacles Are Downright Unsettling

#1: Japanese Spider Crab

Spiders and crabs are some of the creepiest arthropods on their own. So a creature that combines the most horrifying traits of both is especially menacing. Known for their incredibly long leg spans, spider crabs dial everyone’s nightmares about leggy beasts up to 11! Their limbs can span a nope-inducing 12 feet. Their bumpy exoskeleton also allows them to camouflage themselves. Just imagine that creature suddenly rising up out of the sand or the sea! These marine monsters are found almost entirely in the waters surrounding Japan. So if you don’t live or travel to the country, you’ll likely never encounter these. Unless a spider crab is camouflaged behind you right now…