Kraken

The Kraken (/ˈkreɪkən/ or /ˈkrɑːkən/) is a legendary sea monster of giant size that is said to dwell off the coasts of Norway and Greenland. A number of authors over the years have postulated that the legend originated from sightings of giant squids that may grow to 12-15 meters (40-50 feet) in length, despite the fact that the creature in the original tales was not described as having tentacles and more closely resembled a whale or crab. The sheer size and fearsome appearance attributed to the kraken have made it a common ocean-dwelling monster in various fictional works.

https://en.wikipedia.org/wiki/Kraken