OK, OK . . . given that all gods and goddesses are fictional anyway, i'll go with the goddess of the Forgotten Realms, Shar . . .
She is the "Mistress of the Night," the "Nightsinger," the "Lady of Loss." She is described as goddess of dark, night, loss, forgetfulness, unrevealed secrets, caverns, dungeons, the Underdark.
This is Viconia, a devotée of Shar, having renounced the worshipof Llolth, and therefore having been driven from the Underdark:
I don't really give a rat's ass for Shar . . . but Viconia is so hot . . .