Evil Oracle

Steam rises from a stone basin filled with viscous black and purple liquid. Three serpentine creatures surround the pool. Each has the head and upper body of a dark-skinned woman and the lower body of a snake.

Yuan-ti priests use the pool to commune with Dendar the Night Serpent. Three priests named Arakiti, Kultha, and Nyss are here at all times. They are loyal to Fenthaza.
Oracle Pool
The sludge within the pool conducts the reveries of Dendar the Night Serpent. A creature that enters the sludge or starts its turn in the pool takes 5 (1d10) psychic damage.
Any creature that gazes into the pool for more than a few seconds receives a brief, nightmarish vision. In this vision, the creature is being swallowed whole by a giant snake. When the vision ends, the creature must make a DC 15 Wisdom saving throw. On a failed save, the creature takes 5 (1d10) psychic damage and is afflicted with a random form of long-term madness.
Navigation The only way out of this room is the door to the south that leads to the Sacrificial Chamber.