Answer: Owls

There are plenty of creatures that go bump in the night, startle us, and can even harm us, but not every creature makes the cut to be a Halloween spook. Scorpions, for example, scurry around at night and can hurt us, but at best, they are D-list Halloween celebrities. The front-liners of the Halloween animal spook troupe aren’t just night-dwelling and a bit spooky, but come with an attached history.

Owls, for example, can give you a good scare in their own right. They have specially adapted feathers that allow them to glide silently through the night, they’re predators, they have huge eyes that reflect lamplight, and many species have positively haunting calls that seem to carry for miles through the night air.

While that alone might have been enough to get owls past the velvet rope and into the spook club, what really sealed the deal for them was the long-standing belief in Ancient Rome that witches took on the form of owls to fly about on their malicious errands. It was also believed that the calls of owls were an omen of doom. To drive away evil, Romans would nail dead owls to their doors as a superstitious ward. In Ancient Greece, the idea of owls as evil was codified into their lore in the form of the Strix, a mythological owl beast with transfixed eyes that fed on human flesh and blood.

The beliefs of the Ancient Romans and Greeks heavily colored the perception of owls well into the Middle Ages, and medieval Europeans widely associated owls with witches and evil. Today, while most of us simply think of owls as really neat creatures in the urban and rural ecosystems around us (or, perhaps, as special members of the Harry Potter universe), the association of the owl with the celebration of Halloween persists and it’s easy to find Halloween-themed items emblazoned with owls in any shop around the holiday.