The ocean is home to some of the most amazing and bizarre creatures on earth. Exploring the depths of the sea is like entering a whole new world with strange and fascinating creatures.

Deep beneath the ocean’s surface there is a vast abyss where rare and remarkable deep-sea creatures thrive. Researchers from Dalhousie University in Nova Scotia, Canada believe that 91 percent of creatures lurking below the surface are still unknown to us.

Of the 235,000 or so species we do know about, many have adapted to their environment with peculiar camouflage, bioluminescence, and mating habits—leading to some seriously strange appearances.

We’ll take a closer look at 20 of the weirdest deep-sea creatures that will leave you speechless.

1. Leafy Sea Dragon

This may look like your average piece of seaweed but, believe it or not, it’s actually a fish! Found along the southern and western coast of Australia, the leafy sea dragon is a member of the same family as the seahorse – the Syngnathidae family. They grow to around 20-24cm long and feed on plankton and small crustaceans. Moving through the water using their tiny fins, this fab fish’s long, leafy extensions allow it to hide from predators by blending in with seaweed!

2. Flapjack octopus

The flapjack octopus is undeniably cute. Its large eyes, stumpy webbed arms and ear-like fins on its mantle make this octopus adorable. The flapjack octopus spends most of its time on the seafloor, where it can lay flat and resemble a pancake — hence its name. When it’s time to move, the flapjack octopus swims or hovers above the seafloor by flapping its fins and pulsing its web of arms, making it look more like a pulsating jelly than an octopus. Unlike many shallow-water octopus species, the flapjack octopus lacks an ink sac and can’t change color to camouflage.

3. Japanese Spider Crab (Macrocheira kaempferi)

The Japanese spider crab is one gangly deep-sea creature. Known for having the largest leg span of any crustacean — up to 12 feet from claw to claw — this crab looks like an oversized spider. Despite its large size, the Japanese spider crab is not a ferocious predator. Instead, it uses its long, spindly limbs to slowly stroll across the seafloor as it scavenges for dead and decaying matter. Another fun fact — young Japanese spider crabs sometimes adorn themselves with sponges or kelp, possibly to camouflage themselves from predators.

4. Goblin Shark

The Goblin Shark is a rare and peculiar-looking deep-sea shark with a distinctive protruding snout, long and flattened jaws, and sharp teeth. It is mostly pinkish-grey in color, has a soft and flabby body, and can grow up to 3 meters in length.

5. Vampire Squid

The Vampire Squid, also known as Vampyroteuthis infernalis, is a small cephalopod species found in deep ocean waters. It has distinctive red eyes and webbing between its arms, giving it a bat-like appearance. The species is known for its ability to survive in extreme conditions and its unique feeding habits.

6. Viperfish

The Viperfish is a deep-sea fish known for its long, needle-like teeth and bioluminescent lure used to attract prey. It can be found in the depths of the ocean and is well adapted to survive in the extreme pressure and darkness of this environment.

7. Peacock Mantis Shrimp

Found in the Indian and tropical western Pacific oceans, the peacock mantis shrimp is a candy-colored crustacean known for its ability to quickly “punch” prey with its front two appendages. According to Oceana, the international ocean preservation advocacy group, this shrimp’s punch is one of the fastest movements in the animal kingdom—so much so, that it’s strong enough to break an aquarium’s glass wall. But no worries: They mostly only use their fists of steel to break open mollusks and dismember crabs.

8. Pink See-Through Fantasia

The pink see-through fantasia is a sea cucumber, found about 1.5 miles deep into the Celebes Sea in the western Pacific, east of Borneo. It was only discovered a little over a decade ago, back in 2007, but the curious sea cucumber has a survival tactic that points to its longtime evolution: bioluminescence to ward off predators. The pink see-through fantasia is named for its transparent skin, through which its mouth, anus, and intestines are all visible.

9. Frilled Shark

The frilled shark, Chlamydoselachus anguineus, is one of the gnarliest looking creatures in the sea. If it looks like an ancient beast, that’s because it is: the prehistoric creature’s roots go back 80 million years. The frilled shark can grow to about seven feet long and is named for the frilly appearance of its gills. Although shark in name, these animals swim in a distinctly serpentine fashion, much like an eel. They mostly feed on squid, usually swallowing their prey whole.

10. Christmas Tree Worm

Scientists found this strange creature at the Great Barrier Reef’s Lizard Island and named it, aptly, the Christmas tree worm. The spiral “branches” are actually the worm’s breathing and feeding apparatuses, while the worm itself lives in a tube. These tree-like crowns are covered in hair-like appendages called radioles. These are used for breathing and catching prey, but they can be withdrawn if the Christmas tree worm feels threatened.

11. Gulper Eel

The gulper eel (also referred to as the pelican eel) is named for its massive mouth and jaw, which helps them to swallow prey whole. They can grow up to six feet in length and their huge mouths allow them to hunt down meals that are larger than them. This usually happens when food is scarce—it’s believed that gulper eels usually eat crustaceans and other small marine animals.

12. Sea angel

Sea angels are small, swimming sea slugs whose transparent bodies and graceful flapping wings make them look more celestial than slug-like. These cold water inhabitants of the deep sea are modified gastropods — the muscular foot common in gastropods (snails and slugs) has evolved into wing-like appendages for strong swimming in open water and their shells have been lost.

Sea angels use their radula and tentacles to pull other swimming snails from their shells and devour them. They prey exclusively on Clione limacina, a species of shelled pteropods which are expected to be negatively impacted by climate change and ocean acidification.

13. Giant larvacean

Despite its name, a giant larvacean is less than 10 centimeters (four inches) long. But this small, free swimming invertebrate is an incredible mucus architect. Giant larvaceans create an elaborate structure from slimy mucus that can be up to three feet across — its very own snot palace. The larvacean uses the structure to catch food in the marine snow drifting down from the waters above. If the mucus filter becomes clogged, the giant larvacean can quickly ditch it and build a new one. The abandoned mucus house sinks to the seafloor where it provides important food and nutrients to other animals in the deep sea.

14. Marrus Orthocanna

Like a multi-stage rocket, this bizarre microscopic creature, Marrus orthocanna is made up of multiple repeated units, including tentacles and multiple stomachs. Technically, they are physonect siphonophores, which are related to the Portugese man o’war. Like ants, a colony made up of many individuals has attributes resembling a single organism.

15. Bioluminescent Octopus

One of the few known octopods known to use bioluminescence (or glowing with its own light), the Stauroteuthis syrtensis octopus lives about one mile deep in the Gulf of Maine. It can position its photophores (light-emitting organs) to fool prey into swimming right into its mouth.

16. Yeti Crab

This furry-clawed crab looks so unusual that when scientists discovered it 5,000 feet deep on a hydrothermal vent south of Easter Island, they designated it not only a new genus, Kiwa, but a new family, Kiwidae—both named for the mythological Polynesian goddess of shellfish. It’s likely blind and may use bacteria in its furry claws to detoxify its food.

1 7.Axolotl

The Axolotl is a unique salamander species that can only be found in certain lakes and canals in Mexico City. Known for its ability to regenerate limbs and its external gills, it is a popular pet and a subject of scientific study.

18. Osedax Worm

Osedax worms are marine creatures that feed on the bones of dead animals that fall to the ocean floor. They lack a mouth and gut, instead housing symbiotic bacteria that help them digest the collagen in bones.

19. Deep Sea Hatchetfish

The Deep Sea Hatchetfish looks like it has seen enough to last a lifetime… and then some. Their tortured faces are not the only noteworthy trait of these marine animals. These fish have developed special adaptations that keep them cleverly hidden from predators. In addition to their narrow body and reflective scales, Deep Sea Hatchetfish have photophores (organs that produce light by a chemical reaction) on their bellies. The photophores camouflage their shadows by emitting light that matches the color and level of light surrounding them, making them almost imperceptible!

20. Halitrephes Massi Jellyfish

This brightly colored sea-dweller, dubbed the Halitrephes Massi jellyfish, lives in the Eastern Pacific Ocean and is rarely seen by humans. So, what’s behind its stunning array of colors? Canals that move nutrients through the jellyfish’s body reflect light to make this brilliant display.