Also known as “The Black Goat of the Woods with a Thousand Young” and “The Black Ram of The Forest with a Thousand Ewes”, Shub-Niggurath is the Great Old One/Outer God of Fertility in Lovecraft Lore. She appears 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 her form or escape to live their own lives elsewhere.
She is the most worshipped of all the Lovecraft deities, which include Druidic and Barbaric cults, Hyberboreans, and Muvians, along with non-humans like the Mi-Go and Nug-Soth. She can be summoned to any woodlands during a New Moon. She is believed to have mated with Hastur to produce the Ithaqua, Zhar, and Liogor. She may also have mated with Hastur to produce her "Thousand Young" but could be produced via fission. She is also believed to have mated with Yog Sothoth.
Shub Niggurath appears before Tatsuya in the first part of Tatsuya's Scenario as a mysterious demon. She states her name "Iä! Shub-Niggurath!" before the two fight. Shub Niggurath can normally be found in Bomb Shelter 8, Monad Mandala, and the EX Dungeon.