What is "nocnitsa"

The Nocnitsa in Slavic mythology, is a nightmare spirit that also goes by the name kriksy, plaksy, plachky, plaksivicy, kriksy-varaksy, kriksy-plaksy, night hag, night maiden. She is referred to as Nocnica or Płaczka in Polish, горска майка (gorska majka), ношно (nošno) in Bulgarian, Шумска маjка (Šumska majka), бабице (babice), ноћнице (noćnice) in Serbian, mrake, vidine in Croatian, nočnine, mračnine in Slovene.

The Nocnitsa is also present in Russian and Slovakian folklore. She is known to torment children at night, and a stone with a hole in the center is said to be a protection from the Nocnitsa. Mothers in some regions will place a knife in their children’s cradles or draw a circle around the cradles with a knife for protection. This is possibly based on the belief that supernatural beings cannot touch iron.