Nogtail

Found in rural areas across Europe, Russia, and America; a Dark Creature (classified as a demon) resembling a piglet, but stunted with narrow black eyes, a thick stubby tail, and long legs. Nogtails curse farms. A nogtail slips into a pigsty and suckles an ordinary pig; the longer it goes undetected, the longer the curse that falls upon the farm. The nogtail is very fast and difficult to catch, but if chased off the farm by a pure white dog it will never return. See the Pest Sub-Division of the Department for the Regulation and Control of Magical Creatures for assistance with nogtail problems (who keep twelve albino bloodhounds purely for this purpose). (FB)

Cormac McLaggen once went hunting Nogtails in Norfolk with his uncle Tiberius, Bertie Higgs and soon to be Minister for Magic Rufus Scrimgeour (HBP7).