The coaches were no longer horseless. There were creatures standing between the carriage shafts. If he had had to give them a name, he supposed he would have called them horses, though there was something reptilian about them, too. They were completely fleshless, their black coats clinging to their skeletons, of which every bone was visible. Their heads were dragonish, and their pupil-less eyes white and staring. Wings sprouted from each wither – vast, black leathery wings that looked as though they ought to belong to giant bats. Standing still and quiet in the gathering gloom, the creatures looked eerie and sinister.
-J.K. Rowling, Harry Potter and the Order of the Phoenix