Dagon

Dagon, the Shadow in the Sea, is the demon lord of aberrance, the ocean, and sea monsters. He holds court in an infinite ocean covered in disconcerting islands and deep-sea trenches filled with incomprehensible sunken cities. He appears as a massive creature with the lower body of an eel, a head reminiscent of deep-sea predators, and four thrashing tentacles in place of arms. Dagon began life as a qlippoth, and no mortal understands his transformation into a demon lord, though it earned him the enmity of his former kin. Dagon is primarily worshipped by boggards, sedacthies, and marsh giants, though desperate or depraved coastal villages have been known to pledge themselves to the demon lord.