Dendar (DEN-dahr)

Dendar, called the Night-Serpent, is an ancient deity  sometimes worshiped by the Yuan-Ti. They are a god of darkness and hunger, possibly parent and progenitor of the deity Szathusa. Szathusa is said to have overthrown Dendar, and forbidden worship of the Night-Serpent, but Dendar-worship is believed to continue in secret, as the dark deity is hallowed in profane rites.
Dendar is believed to sleep coiled in an Astral Domain, waiting for its worshipers to awaken it. When it does awaken, it will swallow the sun and plunge all the worlds into darkness forever.