An original character by oso (toolate) that is a personification of the 'Coprinopsis atramentaria' (formerly 'Coprinus atramentarius') species of mushroom, commonly known as the inky cap or tippler's bane.
While normally edible, it is poisonous when when ingested in combination with alcohol.
Her name is listed on oso's website and in his artbook as "Kurohiji Hitoyo" (黒肥地一夜.)