Ministry of Magic
Thestrals are an elusive, carnivorous species of winged horse, visible only to those who have witnessed and embraced a death, and described as having "blank, white, shining eyes," a "dragonish face," "long, black manes," "great leathery wings," and the "skeletal body of a great, black, winged horse"; also described by Hagrid as "dead clever an' useful", and also by Harry as "reptilian". They have acquired an undeserved reputation as omens of evil. The High Inquisitor from the Ministry of Magic, Dolores Umbridge, asserted that Thestrals are considered "dangerous creatures" by the Ministry of Magic, although this might be due to her prejudice against 'half-breeds', as Hagrid is half-giant and is showing thestrals in class.