Kraken

Kraken (/ˈkreɪkən/ or /ˈkrɑːkən/) are legendary sea monsters of giant proportions said to dwell off the coasts of Norway and Greenland. The legend may have originated from sightings of giant squid that are estimated to grow to 13–15 m (40–50 ft) in length, including the tentacles. The sheer size and fearsome appearance attributed to the kraken have made it a common ocean-dwelling monster in various fictional works.

Source: http://en.wikipedia.org/wiki/Kraken