Acheri are disease spirits in India’s folk tradition. These spirits live in the mountains and come down to the villages at night. They take the form of innocent little girls, either unknown children or the ghosts of little girls who have died to disease. She looks for those her own size (that size being a child’s size obviously), and if she casts her shadow upon a person he or she will become fatally ill.
One can ward off these spirits however, with the colour red. They will not harm those who are wearing the colour red. So if you tie a red scarf or a red thread around a child’s wrist or neck, they will be safe from the Acheri.