A plethora of interpretations have emerged throughout human history. For some, the lunar features formed the silhouette of a rabbit. For others, the eyes and mouth of a human face.

Armed kids shine light on Mexico's drug cartel violence 06:40. Residents of a town in north-central Mexico were stunned to see a dog running down the street with a human head in its mouth.

"By creating a tsantsa, the soul is trapped inside the remains as the eyes and mouth are closed so there can be no unintended impact on the living from the spirit's power," the study said.