Creatures That Live So Far Underwater They Never See Light, Ranked By Creepiness

The fanfin anglerfish may be the most well-known of the creepy sea creatures, with its glowing lure jutting out of its head to attract prey in the dark depths of the oceans, spindly teeth haphazardly sitting in its mouth, and a general expression of fury. This fish takes the shudder factor up a notch by adding long, bioluminescent filaments to its hunting toolkit. These filaments are able to move independently instead of floating along with the currents of the water. If a web of bioluminescent filaments floating around the fish isn't enough, however, the mating ritual of this creature is also truly terrifying. 

The male attaches himself to the female via biting and the two morph into one creature, sharing a circulatory system forever. The male gains sustenance from the female while periodically fertilizing her eggs for the rest of their lives. 

The mouth of the sarcastic fringehead appears as normal as any other fish mouth when closed, but if a predator or rival attempts to confront them, that mouth opens up to nearly four times its normal size, exposing a rainbow-colored interior ringed with dozens of sharp, curved, and overlapping teeth ready to rip something to shreds.

The fringehead's monstrous mouth evokes memories of the titular movie alien in The Predator. The less aggressive state of the small fish, however, appears more akin to a harmless aquatic pal of the Little Mermaid. 

The goblin shark lives up to its name, looking like a creature from movies like Legend or an orc from The Lord of the Rings. The protruding snout of the goblin shark senses electric fields in the water, allowing it to "see" in the deepest, darkest circumstances. 

Its jaw, fixed below the snout, can be extended all the way out to the end of its snout, allowing it to ambush its prey. Some of these sharks have even been mistaken for other creatures because of their protruding jaws. The goblin shark feeds on fish, squids, and crustaceans, and can range in color from pink to purple to grey.

The dragonfish is barely the size of a pen or pencil but it harbors terrifying, invisible teeth used to capture its prey. The teeth are comprised of the same building blocks as those found in humans, with the difference being the arrangement of the molecules, allowing light to pass through the teeth instead of reflecting off of them.

This means the dragonfish can lull its prey into a false sense of security - why be afraid of a toothless pencil? - before biting into animals up to half its own size. 

The frilled shark lives in the dark depths of the ocean and is often referred to as a relic of the days when dinosaurs roamed the Earth and seas. It can reach a length of 7 feet and swims in an undulating, eel-like fashion. Not only does it have over 200 long teeth with three points of barbs, but those teeth are also arranged in long rows all over its mouth.

The frilled shark can rip into a soft body with no problem, but prefers to swallow its prey whole - even prey up to half its own body size.

A relative of more familiar crustaceans, the giant isopod is a meat-eater, devouring even whales when it encounters one that has recently perished. Since this creature is essentially an extra-large species of the woodlice one might find in their own backyard, its metabolism is extremely slow, allowing it to survive for years without food if necessary. When they do spot prey, their four sets of jaws allow them to munch on even the toughest morsels.

They live in the dark parts of the ocean, using their senses to navigate, and the hooked claw protrusions on their legs pull their 30-centimeter-long frames around.