Mural fragment depicting a priest as Storm God of Teotihuacan

Among the thousands of objects discovered during the excavation of the ruins of the Aztec Main Pyramid in downtown Mexico City was a pair of spectacular ritual water jars, modeled with the mask of the deity Tlaloc and painted brilliant blue (see fig. 1). The goggled eyes, fanged mouth, and heron feathers repeat the features on carved wooden and turquoise-inlaid masks worn by religious performers who appeared as Tlaloc in festivals held in the Aztec capitals (see figs. 2, 3). The cult of Tlaloc …