There have been reports of this creature, also called the California Mountain Devil, since the 19th Century. Its range is said to extend from the south-west USA into Mexico. It is said to be winged with fur, talons and poisonous fangs. A number of them are supposed to have attacked a coachload of settlers in the Sierra Nevada in 1878. 37 of them are said to have been killed, the only survivor being a priest who witnessed the massacre and described the attackers as "winged demons".
No sightings of these creatures have been reported since 1928. Zoologists tend to be dismissive of the creature's existence, regarding it as folkloristic in nature.