It's the cooler, more socially progressive cousin of the Loch Ness monster, and it's finally been caught on tape.
A cameraman has shot footage of what appears to be a giant serpentine creature weaving its way through the icy waters of lake Lagarfljót in east Iceland.
While there have been several sightings of the Lagarfljótsormurinn or “Icelandic worm monster” in modern times, sceptics have suggested this latest iteration is probably just a fishing net caught in the tide.
Legend has it that the Lagarfljótsormurinn started life as a tiny worm placed under a gold ring.
As a fully grown monster, it roamed the countryside, spitting poison and terrorising the local villagers.
While it was eventually thrown into the lake, it was never destroyed, and continues to bring bad luck to everyone it encounters.