The Kraken is the largest Whistimmu ever discovered in Wraith: The Oblivion. The Kraken is terrifying because of its sheer size; it is so big, in fact, no wraith has ever reported seeing it in its entirety. It is known to have tentacles and massive eyes, but nothing else is known of its form or anatomy. The Kraken is also quite ancient; the Great Library of Stygia has reports of it existing before Charon had completed building his great kingdom on the Isle of Sorrows.
Like all Whistimmu, the Kraken appears in the fierce storms of the Tempest, but it actually appears to exist somewhere beyond it, only able to reach through the occasional nihil to terrorize wraiths. Some think it is an embodiment of Oblivion, while others think it is a powerful being that makes the Malfeans look like Striplings by comparison.