The pooka may be regarded as being either menacing or beneficent. Fairy mythologist Thomas Keightley said "notions respecting it are very vague," and in a brief description gives an account collected by Croker from a boy living near Killarney that "old people used to say that the Pookas were very numerous...long ago..., were wicked-minded, black-looking, bad things...that would come in the form of wild colts, with chains hanging about them." and that did much to harm unwary travellers.[6] Also, children were warned not to eat overripe blackberries, because this was a sign that the pooka has befouled them.