A breed of winged horses, Thestrals were special creatures, as they were visible only to those who had witnessed death. Their incorporeal form reflected their connection to the afterlife, and with skeletal bodies, reptilian features and wide bat-like wings, they were unsurprisingly known as bad omens despite their intelligence and loyalty to some humans. Thestrals were native to the British Isles and Ireland and were used to pull the Hogwarts carriages, unbenownst to the majority of the students.