Common superstitions: Black cats are bad omens
The backstory: Despite centuries of royal treatment (Egyptians worshipped them; the Norse goddess Freya rode in a chariot pulled by them), cats took a big hit to their reputation in the 1200s, when Pope Gregory IX, waging a culture war on pagan symbols, damned cats as servants of Satan. As a result, cats—especially black ones—were killed across Europe. One unintended consequence, according to some historians: The cat-deprived continent may have allowed disease-carrying rodents to flourish and spread the bubonic plague of 1348. Rumours that the feline’s fangs and fur were venomous persisted, and by the witch-hunting days of the 1600s, many Puritans believed black cats to be “familiars”—supernatural demons that serve witches—and avoided them (to borrow an apt phrase) like the plague.