A mythical cryptid of epic proportions, the kraken is a sea-monster of Scandinavian mythos that has a non-cryptid (as in an actual confirmed animal) Southern counterpart!
Sea monsters have always been a thing; since the ocean is deep, dark, and temperamental, it lends to the creation of strange things in its depths. The kraken is a well known version of these monsters, with supposed sightings around Greenland and North Atlantic.

The kraken was originally described in detail in the natural history work Konungs skuggsjá (circa 1250), though it was called the hafgufa and later changed to kraken. The anonymous author described everything from the physical characteristics down to the feeding habits.
Due to only being sighted around Greenland and seeming to never have an increase in reported numbers, it was believed that only two kraken existed and were unable to reproduce.
(I’m not fully sure why they jumped to this conclusion, instead of the idea that it was just a unique underwater habitat near Greenland and a rare deep-sea species… But sure, specifically two non-reproducing krakens exist.)
Since then, more reports of a giant octopus-like sea creature has popped up in the Arctic Sea. However, nowadays the old sightings are thought to have been misidentifications of some type of giant squid.
The largest known squid species (in terms of mass) is the Colossal squid. This sea titan is found in the deep Antarctic Ocean and is estimated to grow up to 9 – 10 meters (30 – 33 feet)!
While it isn’t exactly the mythical kraken, the deep sea giants of the earth are certainly terrifyingly strange enough to stoke the imagination of sailors in the past, present and future.

Colossal Squid image from WikiMedia Commons. Other images from Flickr. All images on this site are free usage!