The Coat of Arms of Mexico – Taqueria Vallarta, 24th Street Near Folsom, Mission District, San Francisco, California

The coat of arms of Mexico has been an important symbol of Mexican politics and culture for centuries. The coat of arms depicts a Mexican golden eagle perched on a prickly pear cactus devouring a snake. To the people of Tenochtitlan this would have strong religious connotations, but to the Europeans, it would come to symbolize the triumph of good over evil.

The coat of arms recalls the founding of Mexico City, then called Tenochtitlan. The eagle was a representation of the sun god Huitzilopochtli, who was very important, as the Mexicas referred to themselves as the "People of the Sun". The cactus (Opuntia ficus-indica), full of its fruits, called "nochtli" in Nahuatl, represent the island of Tenochtitlan. To the Mexicas, the snake represented wisdom, and it had strong connotations with the god Quetzalcoatl.

The story of the snake was derived from an incorrect translation of the Crónica mexicáyotl by Fernando Alvarado Tezozómoc. In the story, the Nahuatl text ihuan cohuatl izomocayan, "the snake hisses", was mistranslated as "the snake is torn". Based on this, Father Diego Durán reinterpreted the legend, so that the eagle represents all that is good and right, while the snake represents evil and sin. Despite its inaccuracy, the new legend was adopted because it conformed with European heraldic tradition. To the Europeans it would represent the struggle between good and evil. Although this interpretation does not conform to pre-Columbian traditions, it was an element that could be used by the first missionaries for the purposes of evangelism and the conversion of the native peoples.