Kraken

A giant, cephalopod-like Infernal Demon said to live in the swamp known as Stygia, a swamp filled with the ichorous blood of demons and located on the far rim of Inferno. Usually lurking at the bottom of the swamp, Kraken is said to only rise from the depths and appear on the "Day of Tears", a day that comes only once every thousand years when a rain of blood falls. However, no one has ever seen its full form. It is believed to have ten tentacles, with two of them ending in sharp, anchor-like hooks that it uses to tear into prey, and that its body splits open like flower petals to reveal a giant, voracious mouth. No witch has ever contracted this demon, contributing to the veil of mystery that surrounds it.

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Our Demons Are Different