According to the folklore, Estries are particularly active during the night and can be found preying on young men or newborn babies. They are often depicted as seductive and alluring, luring their victims into a false sense of security before attacking them. They are said to have a particular taste for blood and are often depicted as having fangs or sharp teeth.
In some versions of the legend, Estries can only be defeated by a particular type of wood, such as ash or hawthorn. They are also said to be vulnerable to religious symbols or holy water.
The legend of Estries is particularly prominent in French and German folklore, and similar creatures appear in other European legends as well. While the exact origins of the legend are unclear, it is likely that the story of the Estries evolved from earlier legends and beliefs about demons and witches.