Saga of the Serpent's Skull
The serpentfolk are an ancient race of warmblooded, snake-headed reptilian humanoids who once controlled a vast empire in the time before the Age of Darkness. Their empire collapsed, defeated by the rising Azlanti, coinciding with the beheading of their god Yig, but the serpentfolk evaded total extermination by fleeing into the Darklands. Since that time, they have descended farther and farther into the land below; the last known sitings were made by Pathfinder expeditions shortly before the Earthfall.
Reports indicate that the ancient serpentfolk empire was one of the oldest of all sentient cultures on Golarion, expanding out from the deeper Darklands to conquer much of the surface world. In their wake, they have left numerous smooth stone obelisks which radiate magic, and bas-reliefs telling tales of powerful rituals, blood magic, alchemical science run amok, and service to the Dark Tapestry. These sculptures depict swirling snakes and phalanxes of snake-headed humanoids, crushing entire species under the heels of their saurian mounts. The strangest report is a snippet of text, briefly mentioning creatures reformed with saurian shapes through dread alchemy.
Several of today’s races are descended from the slave-soldiers or alchemical creations of the serpentfolk, though the vast majority have become extinct. Of these, hushed whispers of the serpentfolk remain most present with the morlocks: the reptilians, once masters of the land above and below, are now the bogeymen who catch naughty morlock young unawares.
The last known reports of serpentfolk put them in the middle layers of the Darklands. They have descended into bestial savagery, prowling the underground ruins of their ancient cities; the larger body of the race is a degenerate, inbred branch of the once-powerful race. Few true serpentfolk remain; these highly intelligent individuals lay plans for their people’s return to the arcane supremacy of their past glory, when their thaumaturges performed world-shaking rituals, and their mage-chiurgeons worked great feats of science and alchemy.