Kraken are legendary sea monsters of gargantuan size, said to have dwelled off the coasts of Norway and Iceland. The sheer size and fearsome appearance attributed to the beasts have made them common ocean-dwelling monsters in various fictional works.
The legend may actually have originated from sightings of real giant squid that are estimated to grow to 13 metres (46 feet) in length, including the tentacles. These creatures normally live at great depths, but have been sighted at the surface and reportedly have "attacked" ships.
These huge, many armed creatures would attack a ship by wrapping their arms around the hull and capsizing it, resulting in the crew drowning or being eaten by the monster. and sometimes can thrust its tenticles down with so much velocity it can snap a large ship in 2 parts.