Baba Yaga

Baba Yaga or Baba Roga (also known by various other names) is a hag or witch in Slavic folklore. She flies around on a giant mortar, kidnaps (and presumably eats) small children, and lives in a hut that stands on chicken legs. In most Slavic tales, she is portrayed as an antagonist; however, some characters in other mythological stories have been known to seek her out for her wisdom, and she has been known on rare occasions to offer guidance to lost souls. According to Vladimir Propp, she often fulfills the function of donor; that is, her role is in supplying the hero (sometimes unwillingly) with something necessary to further his quest.

Read more about Baba Yaga:  Etymology and Origin, Folklore, Modern Portrayals