The sculptural tradition of Late Classic (AD 600-900) western Estado de México and adjacent eastern Michoacán is seldom discussed by scholars. This paper provides a reassessment and in-depth iconographic analysis of one of its key monuments, Ixtapan del Oro Monument 1, and argues that the sculpture represents a manifestation of the War Serpent with a deceased warrior emerging from its maw. The sculpture is part of a regional tradition that contributed to Xiuhcoatl ("fire serpent") symbolism of the later Toltec and Mexica cultures, and perpetuated an ideology of militarism and fiery apotheosis of deceased warriors.