Eulagisca gigantea is a large scale worm found in the frigid waters of Antarctica. It features a strikingly bristled appearance with iridescent scales and a distinctive, wide, fanged mouth. This polychaete is a predator, using its powerful jaws to capture prey. It plays a role in the benthic ecosystem, contributing to marine biodiversity.

Eulagisca gigantea, commonly known as the Antarctic scale worm, is native to the Southern Ocean, specifically around the Antarctic continent. It is frequently found in areas such as the Weddell Sea and the Antarctic Peninsula.

Eulagisca gigantea inhabits cold, deep-sea environments typically ranging from depths of 100 to 750 meters. The waters in these regions are characterized by low temperatures, often just above freezing, and high salinity. The sea floor in these areas is often covered with soft sediments.

As a benthic polychaete worm, Eulagisca gigantea plays a role in the deep-sea ecosystem by contributing to the benthic community's biodiversity. It is part of the detritus food chain, feeding on organic matter and other small organisms found within the sediment. This species is also known for its adaptations to cold environments, such as antifreeze proteins that allow it to survive in freezing temperatures.