Uncanny valley

Anthropology major answer: “There absolutely was such a time! Modern humans and our ancestors shared territory numerous times over prehistory with cousin species like homo neanderthalensis, homo floresiensis, and many, many others!”

Folklore student answer: “Also, almost all cultures have something like djinn, faeries, hulder, fox spirits, and other similar creatures who can appear at least human and are very, very dangerous to humans!”