Scientists uncovered the "mystery mollusk," a strange glowing sea creature lurking in the ocean's midnight depths.

An unusual sea slug with a large hood, a tail with fingerlike projections and glowing bioluminescence has been found living off the West Coast of the US.

MBARI researchers have discovered a remarkable new species of sea slug that lives in the deep sea. Bathydevius caudactylus swims through the ocean's midnight zone with a large gelatinous hood and paddle-like tail,

It's named Bathydevius due to its "devious" nature that fooled the scientists at first, while caudactylus refers to the dactyls -- the fingerlike projections on its tail.

“Only recently have cameras become capable of filming bioluminescence in high-resolution and in full color,” Haddock added. “MBARI is one of the only places in the world where we have taken this new technology into the deep ocean, allowing us to study the luminous behavior of deep-sea animals in their natural habitat.”

A "remarkable" new sea slug nicknamed the “mystery mollusk” has been discovered swimming deep in the ocean's "midnight" zone. The species has "unique" adaptations for life in the pitch-black depths including a large gelatinous hood to trap prey,

A “remarkable” new sea slug nicknamed the “mystery mollusc” has been discovered swimming deep in the ocean’s “midnight” zone. The species has “unique” adaptations for life in the pitch black depths including a large gelatinous hood to trap prey,