What is "estries"

Estries are female vampires of Jewish folklore that were believed to prey on Hebrew citizens, particularly men. The name derives from the French strix, a term for a night owl. In some accounts they are considered identical with succubi: both were portrayed as beautiful, blood-thirsty female demons, with Succubi thought to favor babies and young children as prey. Estries, like other vampires, needed to feed on blood to survive and were more indiscriminate in their choice of victims. Succubi were said to kill pregnant women and babies out of jealousy or spite, and to seduce (or in some cases rape) men. Estries and succubi were both said to be able to appear as humans or in spirit form at will, but Estries were also described as able to turn into birds or cats and various other animals.