In the ceremonial center of Tenochtitlan (what it's now Down Town Mexico City), several sculptural representations show the veneration that the natives had for frogs (Cueyatl or Cuiyatl). Some indication exist that the Cueyatl (frogs) are associated with the deity Tlaltecuhtli.
Tlaltecuhtli is the Aztec’s monstrous earth god. Tlaltecuhtli has both feminine and masculine attributes, although she is most often represented as a female deity. Her name means "The one who gives and devours life", and she represents the earth and the sky, and was one of the gods in the Aztec pantheon most hungry for human sacrifice.
According to Aztec mythology, at the origin of time (the "First Sun"), the gods Quetzalcoatl and Tezcatlipoca began to create the world. But the monster Tlaltecuhtli destroyed everything they were creating. The gods turned themselves into giant serpents and wrapped their bodies around the goddess until they tore Tlaltecuhtli's body into two pieces.
Then, Tezcatlipoca and Quetzalcoatl threw a part of her above where it formed the skies while another part of her body became the earth, mountains and rivers; her hair became trees and flowers; her eyes the caves and wells. However, she remained alive and demanded human blood.
Her blood spawned a new breed known as the Cueyatl (frogs, amphibians). So that frogs are recognized as protectors of Tlaltecuhtl, and often regarded as warriors.
-Berdan FF. 2014. Aztec Archaeology and Ethnohistory. New York: Cambridge University Press.
-Matos Moctezuma E. 1997. Tlaltecuhtli, señor de la tierra. Estudios de Cultura Náhautl 1997:15-40.