The Szepasszony is a female spirit in Hungarian folklore, whose name is taboo. She is usually called Fair Lady, or the White Maiden of the Storm, and she adores dancing in all manner of adverse weather. Hailstorms are her personal favorite, and noon is her hour of power. Puddles formed by water dripping from the eaves are her special mirrors for casting magic on bystanders, so it's best to avoid them. If you see a circle of short grass ringed by taller grasses, avoid that too; it's where the Szepasszony dances, and she's generally bad news.
On top of all that, she is of course unbelievably beautiful, and of course, she seduces hapless young men.
Gods & Spirits - E. Europe