The Children Who Appeared From Nowhere—With Green Skin

In 12th-century England, villagers in Woolpit discovered two children wandering out of a pit. Their skin was green, and they spoke an unknown language.

Eventually, the boy died, but the girl lived, learned English, and explained they came from a land with no sun, always twilight. Some historians say it was folklore; others suggest malnutrition. But to this day, their origin is unexplained.