The Yuan-ti are an evil snake people who worship the Snake Goddess Khoisa (also known as Choi). They believe that serpentine form is
inherently superior to human form and perform rituals to become more like snakes. In the depths of time
they ruled a great empire in the jungle and enslaved any humans who would not submit to their rituals.
That empire has been long since destroyed but still the ruins of its ancient cities and temples can be discovered in the jungle.
In modern times cultists still worship Khoisa in secret ceremonies and seek out the forbidden rituals
of her religion by searching for traces of the Yuan-ti culture in the depths of the jungle.