The duran appears in some medieval encyclopedias. It is a cruel, fast and very strong animal. When it is pursued by hunters and their dogs, and is in despair because it sees it cannot escape, it turns on the dogs and slows them down with the putrid odor of its digestion and dung. There are similarities to this in the account of the bonnacon. The encyclopedias refer to Aristotle as the source of this story, but no such reference has been found.