Watch rare footage of a shapeshifting eel with 'remarkably full tummy' swimming in the deep sea

This gulper eel, which was spotted at a depth of almost 7,000 feet by researchers controlling an ROV, has an elongated lump protruding from its underside. Researchers think this bulge was its most recent meal. (Image credit: Schmidt Ocean Institute)

Ocean explorers recently stumbled upon an extremely unusual sight in the Pacific's deep sea — a rare, shapeshifting "gulper eel" with its most recent meal still clearly visible in its stomach.

The pelican eel (Eurypharynx pelecanoides), also known as a gulper eel, was spotted June 20 by researchers on board the Research Vessel (RV) Falkor while controlling the remotely operated vehicle (ROV)  SuBastian. The ROV was on the last dive of the Octopus Odyssey expedition — a mission to investigate an unusually large group of octopuses at the Dorado Outcrop off the west coast of Costa Rica — when it came across the serpent-like fish with a noticeable lump in its midsection around 6,900 feet (2,100 meters) below the surface.