A huge cephalopod like squids and octopuses, the kraken was native to Scandanavian waters, though it is known to travel as far as Greece.
Kraken (Microcosmus marinus)
An aggressive and massive squid, the kraken’s arms are long enough to wrap themselves around the topmast of sailing ships, causing them to capsize. It was in fact so large that it was occasionally mistaken for small islands.
Fish usually grouped around the kraken. Fishermen would try to net those fish, putting themselves in danger not just from direct attack, but from the large whirlpools the kraken would leave in its wake.
Like other cephalopods, krakens were extremely intelligent. Because of this, they usually did not attack humans randomly.
Definitively known around Scandinavia since the 14th century, the kraken is the likely monster described in ancient Greek myths and as the leviathan in the Bible.
No living or dead specimen has ever been caught, though dozens of shipwrecks and hundreds of deaths are attributed to kraken.
It is unknown how long a kraken may live, or how they reproduce.
Extrapolating from other large cephalopod behavior, it is likely that no more than half a dozen survive, given suggested territory and feeding needs. Likewise, their numbers are likely to remain steady, as females usually die caring for the egg sack.
"The UnMuseum - The Legendary Kraken." The UnMuseum - The Legendary Kraken. N.p., n.d. Web. 11 June 2014. http://www.unmuseum.org/kraken.htm
"Kraken." Wikipedia. Wikimedia Foundation, 6 Aug. 2014. Web. 11 June 2014. http://en.wikipedia.org/wiki/Kraken
"Kraken." Kraken. N.p., n.d. Web. 11 June 2014. http://monsters.monstrous.com/kraken.htm