In some cases the kraken is represented as an octopus, or even as a bearded whale. So it depends, really.
I think the myth does originate partially from giant squids, but it’s “glued” with knowledge of smaller cephalopods; it’s easy to picture an octopus but giant, you know? The bearded whale depiction might be related too, possibly some whale hunting a giant squid (they sometimes do it).
I would argue The Colossal Squid is the Kraken but I guess Giant Squids and Colossal Squids tie here.
Colossal Squid have only been spotted in the southern hemisphere, in the near-antarctic southern ocean. Difficult for them to be the source of the myths. They might fit the description better in some respects, but the number of highly unlikely circumstances it would take for one to end up in ancient European myths is pretty astronomical when the Giant Squid is just as close descriptively and much closer in habitat.
More closer to hentai octopus then squids.
