Don’t adjust your sound as this video has none, but wow, does it have a picture! This is a deepstaria enigmatica, a deep-sea jellyfish that was caught by a remotely operated underwater camera about 5000 feet (1500 m) down. Wikipedia places them “in Antarctic and near-Antarctic seas” and puts their size at “approx. 60 cm” (or almost 2 feet) wide. Impressive, nature. Impressive.