A race of rubbery, kelp-haired humanoids who resemble vengeful spirits of the surf. The Sargassan Dreadfolk dwell in magnificent cities woven from living seaweed and bioluminescent coral. Known for their ability to vanish into the greenery of the sea and drag unsuspecting trespassers into the crushing dark, they are often mistaken for demons by surface-dwellers, yet they possess a rich, melancholic culture focused on the preservation of the world's oceans.

Sargassan Dreadfolk possess sleek, rubbery skin ranging in color from deep emerald to olive brown or mottled gold. Their most striking feature is their hair, which consists of actual blades of kelp that continue to grow and float even when they are on land. Their eyes are large and bulbous, often glowing with a faint yellowish phosphorescence to see in the sunless depths. Their fingers and toes are elongated and connected by thick webbing, ending in jagged, hook-like nails designed for gripping slippery rock or struggling prey. When dry, their skin takes on a dull, leathery texture and they emit a pungent scent of salt and decaying brine.

Their society is organized into Great Kelp-Forests, which act as both nations and biological entities. They value silence and patience, reflecting the slow movement of the tides. Art for a Sargassan is not painted but grown; they shape the reefs and weave seagrass into complex, living tapestries. Their culture is matriarchal, led by the eldest Bloom-Mothers who remember the histories of the currents. They have a deep-seated tradition of the Silent Hunt, a rite of passage where a youth must successfully ambush a surface creature to prove they can protect the borders of their watery domain.

The Dreadfolk worship the Tides Above and the Pressure Below, dualistic forces representing life and inevitable death. They tend toward neutral alignments, focusing on the balance of the ecosystem rather than moral absolutes. Some radical sects view the surface world as a parasitic growth that must be pruned, leading to the demonic reputation they hold in human folklore.

They reside in the Churning Spires, massive underwater metropolises located within massive kelp forests. These cities are constructed by weaving the giant stalks of seaweed into spheres and halls, weighted down by stones and reinforced with calcified coral. From the surface, these cities look like nothing more than a dense patch of sargassum, but beneath the waves, they are vibrant hubs of bioluminescent light and flowing currents.

They are cautious of the surface-bound races, whom they call the Bone-Dries. They find the metal-smelting and fire-making of the upper world to be terrifying and unnatural. While they occasionally trade pearls and rare deep-sea herbs for glass and enchanted items, they are most famous for their territorial nature. They maintain a respectful, if distant, relationship with coral-dwelling folk and find goblin-kin of the coasts to be annoying pests.