Xiuhcoatl

thumb|right|An Aztec sculpture of Xiuhcoatl from Texcoco (altepetl)|Texcoco, now in the British Museum In Aztec religion, Xiuhcōātl was a mythological serpent, regarded as the spirit form of Xiuhtecuhtli, the Aztec fire deity sometimes represented as an atlatl or a weapon wielded by Huitzilopochtli. Xiuhcoatl is a Classical Nahuatl word that translates as "turquoise serpent" and also carries the symbolic and descriptive translation of "fire serpent".

Xiuhcoatl was a common subject of Aztec art, including illustrations in Aztec codices, and was used as a back ornament on representations of both Xiuhtecuhtli and Huitzilopochtli. Xiuhcoatl is interpreted as the embodiment of the dry season and was the weapon of the sun. Apparently, the royal diadem (or xiuhuitzolli, "pointed turquoise thing") of the Aztec emperors represented the tail of the Xiuhcoatl, the fire serpent.