Top 8 Spooky Sea Creatures for a Fun Halloween Scare

Boo! Sorry did we scare you? No? Well if you encounter any of the creatures on this list your heart might skip a beat. We’ve compiled a spooky list of some creepy critters you can find in our oceans. Some of them might make you think twice before diving into the water again. “Goblin Sharks, Vampire Squids, and more, OH MY!” Let’s dive in!

Goblin Shark

The Goblin Shark is a strange and creepy creature with fang-like teeth that extend to catch prey at depths of up to 4,000 feet. These slow-moving sharks can grow up to 18 feet long and have a unique hunting method. Since they aren’t fast, they cruise along the ocean floor using their long snout to sense prey. Their snouts are filled with special pores called ampullae of Lorenzini, which help them detect the heartbeat of nearby prey. When ready to strike, their jaws shoot out at over 10 feet per second to snatch and swallow their prey.

Goblin Sharks are pinkish-purple or gray and are usually found between 400 and 4,000 feet deep, most commonly near Japan and New Zealand, though they’ve been spotted worldwide, even off Key West. They mostly eat bony fish, squid, and crustaceans. As one of the rarest sharks, you’re unlikely to see one, though juveniles sometimes appear near the surface. Much about their lifespan and reproduction remains a mystery.

Giant Isopod

Giant Isopods are like oversized versions of the pillbugs you might find in your garden, but they live deep in the ocean, 550 to 7,000 feet below. These isopods can grow up to a foot long, making them a striking example of deep-sea gigantism. Since they have few predators, they can adapt to the extreme conditions of the deep sea.

As scavengers, Giant Isopods feed on dead fish and even whale carcasses that sink to the ocean floor. But since food is scarce, they’ve evolved slow metabolisms and can go long periods without eating—one in captivity survived over five years without eating.

These 14-legged, alien-like creatures use two sets of antennae to search for dead organisms in the dark, thousands of feet below the ocean's surface. The Giant Isopod is just one of over 10,000 isopod species and is thought to live all around the world. In Northern Taiwan, they’re even served as a dish alongside rice and are said to taste like lobster. Yum!

Sea Spider

No Halloween is complete without a creepy spider, and the Sea Spider fits the bill! It can grow up to 20 inches long, making it larger than many land spiders. However, Sea Spiders aren’t true spiders; they belong to a group of arthropods called pycnogonids. They molt as they grow, and larger Sea Spiders can be found at depths of up to 13,000 feet, while smaller ones live in shallower waters.

You’ll notice that Sea Spiders have long legs and very little body. In fact, their legs carry some vital organs, like their digestive tract. They primarily feed on anemones and other soft-bodied creatures by inserting their proboscis and sucking out the insides, similar to a chunky smoothie—gross! They have a slow metabolism, so they don’t need to eat often.

There are over 1,300 species of Sea Spiders found in oceans all over the world. The larger ones tend to live in colder waters near the poles, as well as around South Africa and South America.

Vampire Squid

The Vampire Squid doesn’t actually say, “I want to suck your blood,” but it sure sounds spooky! Living 2,000 to 4,000 feet deep in the ocean’s oxygen minimum zone, where oxygen is as low as 3%, the Vampire Squid survives thanks to its copper-based blue blood, which binds oxygen efficiently. With a low metabolic rate and neutral buoyancy, it doesn’t need to eat much or use a lot of energy. As an ancient cephalopod, this "living fossil" has few predators because so little life exists in the deep.

The Vampire Squid feeds on marine snow—bits of decaying fish, plankton, and even poop—using two retractable filaments. It has large red or blue eyes and grows up to a foot long, with its body covered in light-producing organs called photophores. To escape predators, it releases glowing, sticky mucus from its arms, which can also regenerate if bitten off. Instead of ink, when threatened, the squid flips inside out and hides under its dark webbed arms in a "pineapple posture."

Barreleye Fish

The Barreleye Fish is one of the strangest and most otherworldly creatures of the deep sea. Found at depths of 2,000 to 2,600 feet, this fish is known for its transparent head, which allows it to look upward through its own skull to spot prey in the darkness above. Its tubular eyes are highly sensitive to light, helping it detect the faint glow of jellyfish and other small organisms. The Barreleye’s eyes can rotate, allowing it to focus on potential prey as it swims beneath them. With a small, flat body and fins that help it hover in place, this fish waits for food to drift within reach. Despite its eerie appearance, the Barreleye is a harmless, peaceful predator, surviving in one of the most extreme environments on Earth and continuing to puzzle scientists with its unique adaptations.

Lamprey “Vampire Fish”

Lampreys, also known as Vampire Fish, feed like parasites by using their tooth-filled mouths to latch onto victims. Adult lampreys have around 150 cone-shaped teeth, which help them grip onto fish while their tongue bores into the skin through a process called rasping. Once attached, they suck blood and fluids from the host. Lampreys don’t have jaws or a bony skeleton—just cartilage, similar to sharks.

They start life as larvae, buried in freshwater silt and feeding on algae for about 4 years. Then, they transform into carnivorous adults and move to the sea, growing up to 40 inches with 7 tiny gills. While feeding, they usually attach near a fish’s heart, slowly draining it without killing it in the ocean. However, freshwater species, like those in the Great Lakes, kill 40-80% of their victims, either from the initial attack or later infections. Lampreys are found worldwide, including on the U.S. East Coast and in Florida, but they rarely attack humans. Interestingly, they’re considered a delicacy in Latvia!

Fangtooth Fish

The Fangtooth Fish is a terrifying predator that stalks the deepest, darkest parts of the ocean, up to 16,000 feet below the surface. With its oversized, needle-like teeth—some of the largest in proportion to its body of any fish—it looks like a creature straight out of a nightmare. Despite being only about 6 inches long, its menacing appearance and powerful jaws make it a fearsome hunter in the abyss. The Fangtooth Fish relies on its heightened senses to navigate the pitch-black waters, as its tiny eyes aren’t much use in the darkness. It hunts by ambush, waiting in the shadows for unlucky prey to pass by before striking with lightning speed. With its gruesome looks and deadly bite, the Fangtooth Fish is a true terror of the deep.

Giant Squid

Legend has it that Giant Squids are responsible for sinking ships, inspiring tales of monstrous sea creatures lurking in the depths! These mysterious creatures can grow up to 43 feet long and have huge eyes the size of basketballs, helping them navigate the dark ocean. With long, muscular bodies and eight arms lined with powerful suckers, they catch prey like fish and other squid. Their long tentacles allow them to strike from a distance. Although they are massive, Giant Squids are rarely seen, and much of what we know comes from studying their beaks found in sperm whales, their only known predators. They live at depths of over 3,000 feet and can change color and texture for communication and camouflage. With their intriguing behavior and deep-sea habitat, Giant Squids continue to fascinate researchers and ocean lovers alike.

Thanks for reading our Top 8 Creepy Critters of The Deep blog! Diving isn’t scary. Whether you are looking to get into diving, or an advanced level diver, stop by one of our 4 dive shops in Florida for everything you need. Our experts have been diving for decades and are happy to get you started, or take your diving to the next level! With that being said, Happy Halloween from Divers Direct!

FAQs

What are some of the creepiest ocean critters?

Some of the creepiest ocean critters include the anglerfish, giant isopod, vampire squid, goblin shark, gulper eel, deep-sea dragonfish, and the stargazer fish. These creatures have unique and often unsettling appearances, adapted to the extreme environments of the deep sea.

What is an anglerfish, and why is it considered creepy?

The anglerfish is a deep-sea fish known for its bioluminescent lure, which it uses to attract prey in the darkness of the ocean. The females have large mouths filled with sharp teeth and an eerie, glowing appendage on their heads. Their ghastly appearance and the fact that some species practice extreme sexual dimorphism, where tiny males fuse to the larger females, add to their creepy reputation.

How does the vampire squid get its name?

The vampire squid gets its name from its dark red color and webbing between its arms that resemble a cloak. It also has bioluminescent organs that it uses to create a glowing effect in the dark waters where it lives. Despite its fearsome name and appearance, it feeds on marine snow (organic debris falling from the upper layers of the water) rather than living prey.

What makes the goblin shark so frightening?

The goblin shark is often considered frightening due to its unusual, elongated snout and protrusible jaws filled with nail-like teeth. These jaws can extend forward dramatically to snatch prey, giving it a nightmarish appearance. The goblin shark's pinkish skin and sluggish movement add to its eerie mystique.

Why are giant isopods considered creepy?

Giant isopods are large crustaceans that resemble oversized pill bugs. They live in the deep sea and can grow up to 20 inches in length. Their large size, segmented bodies, and tendency to scavenge on the ocean floor, including feeding on dead whales and fish, contribute to their creepy image.