the Festering Queen is the matron of the Vermin order, and the goddess of Pestilence.
Throughout time she's come head-to-head with Luna and her order of Ravens due to Vermin's innate want to spread disease across the world in order to wipe out the human race and exact control over Earth.
Background
Unlike the new age gods and goddesses (like Luna), Vermin is a primordial god, having existed since before written and even oral history.
Closely related to Death, Life, Spirit, and Earth, she is the matron of the Vermins, her champion is Pestilence, the White Rider.
She is the creator of all known illnesses like scrofula, plague, sepsis, and grippe, and revels in spreading them.