Kraken

Massive, deep-sea dwelling creatures that occasionally surface near the Ship's Graveyard.
Considered by the inhabitants of the Pitch Black forest to be the human plane's sea-dwelling equivalent of crawlers. Not much exists to contradict this theory, given krakens' rapid regeneration rate; gaping, toothy maws; and armored masses of prehensile tentacles.
Weaker, but not helpless, if dragged onto land. Exhibit the same soul-based regeneration as crawlers, although it is less effective when they are not underwater. The draining effect naturally cools surrounding water, resulting in unusually cold water being considered a bad omen by many seafaring cultures.

An interesting fact about kraken meat is that it keeps indefinitely. Remnants of its life-leeching regeneration ability keeps the meat constantly sterile until subsumed by a sufficiently strong soul to halt the process (i.e. being swallowed by a human). Some bold fishing civilizations have attempted to hunt for kraken tentacles: killing the whole beast is impractical, but drawing it out and slicing off a massive chunk of meat from the renewable source is surprisingly effective. Kraken meat is effectively the holy grail of traveler's food: extremely nutrient dense, decently edible, and absolutely impossible to spoil.
The meat itself has the texture of jerky and tastes very strongly of shellfish when raw, oddly cooking like a scallop in reverse: getting softer and more buttery the more it is cooked.

Basic Information

Growth Rate & Stages

The ones that typically surface are around 21m (~70 feet) long, larger ones generally staying far below. Krakens have magical regenerative abilities that drain energy from surroundings, although larger life forms, such as humans, aren't noticeably affected. Because of this, kraken meat is sterile and keeps indefinitely (killing nearby bacteria and small insects), resulting it being considered one of the holy grails of travel rations: tastes great, and impossible to spoil. Obtaining kraken meat is very hard due to their armored carapaces, although some cultures bait them specifically to cut off the unarmored front tentacles before escaping.

Dietary Needs and Habits

Whales, sharks, and giant jellyfish are typical, along with any fish they come across. There's a region known as the Ship's Graveyard where they often surface because it has a link to their elemental plane, making it easier for them to absorb magical energy that can substitute for calories.
Their mouths are great for swallowing things whole or draining existing carcasses, but they don't really have very efficient ways to kill things of similar sizes. Larger ones stay below to take advantage of deep sea gigantism, giving them larger prey. Because of their magical regeneration, they themselves don't have a problem coming to the surface despite the pressure differential, but there isn't enough food for them to stay there.
Since krakens have magic regeneration they don't really care about the pressure differential, they can operate at any depth. However, because most other creatures don't have this ability, mundane gigantic creatures have to stay below. Krakens then follow the larger food source. Krakens are generally optimized to kill things smaller than them, so smaller/younger krakens stick to shallower depths to have an easier time hunting.