Quetzalcoatl, the “Feathered Serpent” or “Plumed Serpent” is one of the most iconic deities of the Mesoamerican pantheon. Sahagun also records a far more mundane creature by the same name.
The quetzalcoatl is found in the province of Totonacapan (Guatemala) and is the size of a medium water-snake. It is covered with feathers just like those of the quetzal bird. There are tzinitzcan, small light green feathers, on its neck, red feathers on its breast, and blue feathers on the tail and rings (coils?).
This snake is rarely seen, and when it does it flies and bites the person seeing it. Its bite is deadly and kills instantly, killing both it and its victim, for it exhales its venom and its life in one go.
Nuttall, Z. (1895) A Note on Ancient Mexican Folk-lore. The Journal of American Folklore, v. 8, no. 29, pp. 117-129.
Sahagun, B.; Jourdanet, D. and Siméon, R. trans. (1880) Histoire Générale des Choses de la Nouvelle-Espagne. G. Masson, Paris.