This diminutive slate mirror back from the Guatemalan Lowlands is carved with one of only two known texts referring to the king known as Yax Yopaat (First Axewielder), an important but little-known ruler of the Snake Dynasty, a powerful ruling lineage of the Maya. The mirror itself appears to have been the property of Yax Yopaat’s otherwise unknown son, whose name is only partially deciphered, “?-Ch’een.”