Eptatretus okinoseanus is a species of hagfish in the family Myxinidae, found in the deep waters of the Pacific Ocean, particularly around Japan. This species is known for its elongated, eel-like body and its ability to produce large amounts of slime as a defense mechanism against predators. As a scavenger, it plays a crucial role in deep-sea ecosystems by feeding on dead or decaying organic matter. Its adaptations to low-oxygen environments and high pressures make it an important species for studying the physiology and ecology of deep-sea organisms.