This giant jellyfish might be the biggest one ever caught on camera in U.K. waters.
According to Metro UK, diver Robert Lenfertwas swimming off the coast of Pendennis Point, Cornwall when he crossed paths with the enormous sea creature. It's one of a specimen of jellyfish known scientifically as the rhizostoma pulmo, or more commonly as the barrel,dustbin-lid or the frilly-mouthed jellyfish.
Evident in the video, which follows the gigantic jellyfish as it drifts peacefully through the English waters, is the creature's great size. Unlike the small handfuls of jelly which we're used to being stung by or seeing wash up on beaches, this particular jellyfish seems to be nearly as large as a fellow human diver who is visible at the start of the clip. It's possibly the largest example of a barrel jellyfish ever filmed in the U.K. - and the barrel jellyfish itself is known as the biggest jellyfish found in British waters, as it is known to grow up to 90 cm (35 in) in diameter.
Record numbers of barrel jellyfish have been seen in the area recently, which experts believecould be a result of pollution, over-fishing or climate change.
Despite the creature's monstrous appearance, it has only a minor sting and is relatively harmless to humans.