It happens at times that a child reports that their parent abandoned them and, soon after, a 'new mother' or 'new father' arrived, with glass eyes and a wooden tail.
The appearance of these creatures is so frightening that, invariably, the child reports that they fled in terror.
The creatures are said to simply stay in the house. They apparently do not need to eat. A pall of fear seems to keep away neighbours as it does the children. Thus they are known only by the occasional flash of their eyes seen through the window, and the muffled sound of their wooden tail.
Some say that these creatures are doing their best to comfort the poor children, but their unearthly nature defeats their aims. Others say that they are simply concerned with gaining access to the parent's property, or to the children themselves. Yet others suggest that their coming is arranged by an Angel of Poetic Injustice enforcing the offhand remark of an exasperated parent.
(Thanks to Swords & Dorkery for the link to the document that inspired this post).