Giant Spider Crab Thought to be the largest arthropods on Earth, giant spider crabs spend their time foraging on the ocean floor up to a thousand feet (300 meters) deep. These rare, leggy behemoths, native to the waters off Japan, can measure up to 12 feet (3.7 meters) from claw tip to claw tip. This five-foot (1.5-meter) specimen was photographed in Japan's Sagami Bay.

Wolffish An orthodontist's dream, an Atlantic wolffish displays the hardware it uses to crush mollusks, shellfish, and sea urchins. These tough-looking predators swim as deep as 2,000 feet (600 meters) and range from the Scandinavian coast to Cape Cod to the Mediterranean.

Fangtooth Fish The nightmarish fangtooth is among the deepest-living fish ever discovered. The fish's normal habitat ranges as high as about 6,500 feet (2,000 meters), but it has been found swimming at icy, crushing depths near 16,500 feet (5,000 meters). Fangtooth fish reach only about six inches (16 centimeters) long, but their namesake teeth are the largest, proportionate to body size, of any fish.

Frilled Shark Humans rarely encounter frilled sharks, which prefer to remain in the oceans' depths, up to 5,000 feet (1,500 meters) below the surface. Considered living fossils, frilled sharks bear many physical characteristics of ancestors who swam the seas in the time of the dinosaurs. This 5.3-foot (1.6-meter) specimen was found in shallow water in Japan in 2007 and transferred to a marine park. It died hours after being caught.

Goblin Shark The goblin shark is a rare species of deep-sea shark. Sometimes called a "living fossil", it is the only extant representative of the family Mitsukurinidae, a lineage some 125 million years old.

Hump Back Anglerfish The deep sea Hump Back Anglerfish is one of the most bizarre-looking fish in the sea. Known scientifically as Melanocetus johnsoni, it is also one of the best-known creatures of the deep. It is one of about 200 species of anglerfish found throughout the world's oceans

The megamouth shark is an extremely rare species of Deepwater shark, and the smallest of the three planktivorous sharks. Since its discovery in 1976, only 60 specimens are known to have been caught or sighted as of January 2015, including three recordings on film.

Vampire Squid Vampire squid is an apt name for a creature that lurks in the lightless depths of the ocean. Comfortable at 10,000 feet (3,000 meters) below the surface, these diminutive cephalopods navigate the blackness with eyes that are proportionately the largest of any animal on Earth. The species gets its name from its dark, webbed arms, which it can draw over itself like a cloak

Pacific Viperfish The Pacific viperfish has jagged, needlelike teeth so outsized it can't close its mouth. These deep-sea demons reach only about 8 inches (25 centimeters) long. They troll the depths up to 13,000 feet (4,400 meters) below, luring prey with bioluminescent photophores on their bellies.

Basking Shark The basking shark is the second largest living fish, after the whale shark, and one of three plankton-eating sharks besides the whale shark and megamouth shark. It is a cosmopolitan migratory species, found in all the world's temperate oceans.