The Dark Sargassum is a fictional monster from the Cthulhu Mythos featured in the role-playing game supplement The Bermuda Triangle.
Description[]
Classified as a "Unique Entity", the Dark Sargassum is a colossal organism spread over a large area within the Bermuda Triangle, in the Atlantic Ocean. This marine terror originated as a Dark Young of Shub-Niggurath which sank with the lost continent of Atlantis and adapted itself to a new environment, mimicking the form of seaweed and feeding off marine life in the area. Now over 11,000 years old, it has grown into a humongous beast that looks and smells like a floating mass of sargassum.
Hidden within its body are over a hundred rope-like tentacles, which are used to capture prey and drag it towards the creature's toothed maw, located near its centre. Due to its size, the Dark Sargassum can encircle and crush ships weighing up to 200 tons. Few people are aware of the monster's real nature, save for the local Deep Ones and the organisation known as the Cult of Sargath, the latter of which congregates every All Hallow's Eve to offer human sacrifices to it. (EXP: The Bermuda Triangle)