The Giant Sea Spider is a species of crustacean seen only in the deepest parts of the ocean.
"Its long, narrow, red body has four pairs of long legs and two pairs of shorter ones that contain its intestines and reproductive organs.The male protects the eggs inside one pair of its shorter legs, known as ovigers. Although it looks like a land-based spider, it is completely classified as a different species."
These can be found under zoom-mode glows scattered about in the Abyss.
This creature is found only under zoom-mode glows, either by itself or with another of its kind. In Endless Ocean 2, The zoom-mode spots this creature occupies are sometimes instead home to a Humpback Anglerfish or two.