There are two variations of “Jilaiya” in Indian folklore. In one portrayal, she assumes the form of a female demon with vampiric characteristics. She sleeps during the day, in dark places untouched by sunlight, but as night descends, jilaiya transformed into either a bat or a bird to hunt for prey. She is said to target individuals whose names are made known to her.
In an alternative version, jilaiya is characterized as a spectral bird or demon bird unhampered by sunlight. Initially indistinguishable from an ordinary bird, those targeted by a jilaiya are said to start noticing unusual behaviors of the bird, such as its lack of fear when approached by a human. According to the legend, the bird demon can kill a person only if it knows their name. If one's true name is kept from the bird, it supposedly becomes powerless and unable to cause harm.