4 Scariest Deep Sea Creatures Ever Discovered

Dive into the depths of the ocean to discover the scariest deep sea creatures, including the goblin shark, spookfish, Japanese spider crab, and zombie worm.

Oct 27, 2023By Natasha Elder
scariest deep sea creatured ever discovered

There’s no denying that the deep sea is a scary place. It’s pitch black, ice cold, and eerily quiet – the place is nightmare fuel. But what is undeniably the scariest part about the deep sea is the terrifying array of creatures that live within it. From those that feast on decaying skeletons to those that have extendable jaws, the deepest depths of the ocean are home to some seriously scary creatures. Without further ado, here are four of the scariest deep-sea creatures ever discovered.

1. Goblin Shark

juvenile goblin shark mitsukurina owstoni
Image credit: Smithsonian

Discovered in Japanese waters in 1898, the goblin shark is a living fossil that slowly creeps its way across the ocean floor. It is the last living member of the Mitsukurinidae family, an ancient lineage of sharks thought to be around 125 million years old, presumably making it the oldest shark species in existence.

This lesser-known shark species is extremely rare and is hardly seen. But every couple of years, it accidentally ends up in the nets of deep-sea fishers. Goblin sharks are slow-moving, stubby, and flabby. Its semi-translucent skin is pink and has a rough texture. It has a broad, flattened head and a long, pointed snout that it uses to find food at the very bottom of the sea. Some sea creatures can live for hundreds of years, but with their estimated lifespan limited to 60 years, the goblin shark isn’t one of them.

Goblin Sharks Feed Using a Retractable Jaw

goblin shark compared to human diver
Image credit: Wikimedia Commons

What truly makes the goblin shark so scary is its extendable jaw. It has up to 53 needle-like teeth on the top and up to 62 on the bottom. When it senses food is nearby, it launches its jaw out of its mouth. Once it’s done eating, it retracts its jaw back into its mouth and goes back to trawling the ocean floor.

2. Japanese Spider Crab

japanese spider crab deep sea crustacean

One of the creepiest crustaceans known to man, the Japanese spider crab was first discovered in 1836 in Japanese waters. Crabs, in general, can be a little unsettling, what with their 10 regenerating legs, tough armored body, beady little eyes, and strange sideways scuttle. But the enormous Japanese spider crab is downright frightening.

Japanese spider crabs’ legs can measure up to 12.1 feet (3.7 meters), and they weigh around 44 pounds (20 kilograms). Can you imagine being underwater and seeing this monstrosity swimming towards you? This scary spider crab is a prime example of deep-sea giantism in action.

These scary-looking crabs are just that: scary-looking. Though they are horrifically huge, they’re completely harmless and are known to be quite docile – they don’t even actively hunt for food, but scuttle along the ocean floor scavenging for scraps of decaying flesh instead. The Japanese spider crab takes the term “gentle giants” to a whole new level.

3. Spookfish

barreleye fish spookfish deep sea
Image credit: Wikipedia

No list of scary deep-sea creatures would be complete without mentioning the spookfish. This aptly named creature, which is also known as a barreleye, was discovered in 1939. It travels between different deep-sea zones and is usually found lurking in either the mesopelagic zone (the twilight zone) or the bathypelagic zone (the midnight zone.)

What’s in a name? Well, on the one hand, this fish is called the barreleye due to the barrel-like shape of its tubular, green-lensed eyes that are known to stare upwards. On the other hand, this fish is called the spookfish because its head is completely see-through, so its strange eyes don’t need to worry about something inconvenient – like skin -- blocking its view.

model of a spookfish by museum
Image credit: Wikimedia Commons

Another slightly spooky aspect of the spookfish is its hunting style. Because of its large, flat fins, it is an expert hoverer, and this allows it to be motionless while it sits and waits for its prey, seemingly not moving a muscle. Thankfully, the spookfish is on the small side and only grows to around 6 inches (15cm) in length – not that this does much to decrease its overall level of scariness.

4. Zombie Worms

osedax packardorum zombie worms
Image credit: MBARI

Back in 2002, zombie worms were discovered 10,000 feet (3,000 meters) down in Californian waters. What were these strange fuzzy red worms doing when they were discovered? Nothing crazy, just devouring the bones of a dead gray whale. Although they were only discovered early in the millennium, palaeontologic evidence suggests these bizarre bone-eating worms have been around for around 100 million years.

There are just under 30 known species of zombie worms. Some are no bigger than an eyelash, while others can reach lengths up to 3 inches (7cm). All feast on the bones of sunken dead creatures. They do so without the help of a mouth, stomach, or anus. If that’s the case, how do zombie worms eat? These frightening worms latch onto bones, burn into them with an acidic secretion, and suck the marrow straight out.

Zombie worms mainly eat whale skeletons and the remains of bony fish, but they also have been known to eat shark teeth. It is thought that many years ago, plesiosaur and mosasaur bones were the zombie worm’s favorite food.

Natasha Elder
By Natasha Elder

Natasha is a mother, a wife, a writer, and a serial cat owner. Though she is currently in mourning, her heart not ready for another feline family member just yet, she has always lived life with four paws beside her. She loves – you guessed it – cats, as well as creatures of the fluffy, scaly, and finned variety. Natasha longs to meet Sir David Attenborough one day and is passionate about responsible pet ownership