Kraken

Krakens are colossal, deep sea cephalopods native to the Abyssal Ocean. A fully grown kraken can easily reach lengths of up to 230 meters.
Krakens live at the bottom of the ocean, on the sea floor. They have been known on rare occasions to ascend to the surface and attack ships during storms, however this is considered to be exceptionally abnormal behavior for their species. On the rare occasions that a kraken does visit the surface, it is most likely due to a mental illness or disorder paired with an attraction to lightning.
Krakens were once considered to be myth and legend, but their existence was proven in 7M102Y when a kraken carcass washed up on the western shores of Shadeniin. Marine biologists have been tracking them ever since.