This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Sceadugenga (English)
The Sceadugenga, or "shadow-goer", are fantastical beasts which are neither living nor dead, and which can shape-shift. They dwell in the forests of England. In some tales they often take the form of children, acting likecuckoos by moving into a village and settling down with a compassionate family. They stay to get both food and companionship as they are solitary for the majority of their life.
When they feel like the attachment is too much or when they become bored they often leave to return to the forest. However, they will stay with humans indefinitely if they fall in love with or form an attachment to a human. Over time, they lose their abilities and forget what they once were, living out the remainder of theirexistenceas a human.