Shub-Niggurath is an Outer God in the pantheon. She is a perverse fertility deity said to appear as an enormous cloudy mass which extrudes black tentacles, slime-dripping mouths, and short, writhing goat legs. Small creatures are spat forth, which are either reconsumed into the miasmatic form or escape to some monstrous life elsewhere.
Of all the mythos deities, Shub-Niggurath is probably the most extensively worshiped. Her worshipers include the Hyperboreans, the Muvians, and the people of Sarnath, as well as any number of druidic and barbaric cults. She is also worshiped by the non-human species of the mythos, such as the "Fungi from Yuggoth" (the Mi-Go ) and the Nug-Soth of Yaddith.
Shub-Niggurath can be summoned to any woodlands at the time of the new moon. However, the place from whence she comes is not known. One possibility is that she dwells at the court of Azathoth at the center of the universe. She may also live beneath the planet Yaddith, where she is served by the Dholes. It is also possible that she lives in another dimension altogether.