The term 'Deep Sea Denizen' refers to creatures that inhabit the depths of the ocean. The three solutions for this term are OCTOPUS (7 letters), Cthulhu (7 letters), and Lanternfish (11 letters). Octopuses are cephalopods with eight arms and two eyes, and they are found in tropical and temperate oceans around the world. Cthulhu is a fictional creature created by author H.P. Lovecraft, described as a monstrous entity of immense power. Lanternfish are small, bioluminescent fish that live in the deep sea, and they are an important food source for many larger predators.