Plague Bearers: Embodiments of Disease
Humankind has always been at the mercy of plagues, great sweeping illnesses that destroy whole populations then vanish mysteriously. We now blame these great plagues on microbes, bacteria, and viruses, but in the distant past no one knew or believed in these things; illnesses were instead blamed on such things as bad air, punishments from divine forces, and evil spirits... often in human form. One of the best sources of such old beliefs was Jacob Grimm's (yes, of the Brothers Grimm!) 1835 study, Deutsche Mythologie (Teutonic Mythology), which treated of this topic in one of its chapters. It's seems possible that this same study may have inspired Edgar Allen Poe's 1842 short story The Mask of the Red Death: A Fantasy, in which nobles trying to hide from a plague ravaging the world outside their walls are accosted by the plague itself in human guise.
Below is a listing of the legends gathered by Jacob Grimm, to which I'm also adding accounts of actual plague bearers that have been discovered.