In Slavic folklore, Baba Yaga is a supernatural being (or one of a trio of sisters of the same name) who appears as a deformed and/or ferocious-looking woman. Baba Yaga flies around in a mortar, wields a pestle, and dwells deep in the forest in a hut usually described as standing on chicken legs (or sometimes a single chicken leg). Baba Yaga may help or hinder those that encounter or seek her out. She sometimes plays a maternal role, and also has associations with forest wildlife. According to Vladimir Propp's folktale morphology, Baba Yaga commonly appears as either a donor or villain, or may be altogether ambiguous.
Andreas Johns identifies Baba Yaga as "one of the most memorable and distinctive figures in Slavic European folklore," and observes that she is "enigmatic" and often exhibits "striking ambiguity." Johns summarizes Baba Yaga as "a many-faceted figure, capable of inspiring researchers to see her as a Cloud, Moon, Death, Winter, Snake, Bird, Pelican or Earth Goddess, totemic matriarchal ancestress, female initiator, phallic mother, or archetypal image".
The first clear reference to Baba Yaga (Iaga baba) occurs in 1755; Mikhail V. Lomonosov's Rossiiskaia grammatika ('Russian grammar'). In Lomonosov's grammar, Baba Yaga is mentioned twice among other figures largely from Slavic tradition. The second of the two mentions occurs within a list of Slavic gods and beings next to their presumed equivalence in Roman mythology (the Slavic god Perun, for example, appears equated with the Roman god Jupiter). Baba Yaga, however, appears in a third section without an equivalence, attesting to perception of her uniqueness even in this first known attestation.