This black-line drawing of the simplex glyph for Ecatl, which literally means air or breath. The visual, however, refers to the divine force or spirit of the wind, Ehecatl). It shows a face in profile, facing to the viewer's right, and the face has duck-bill-like protrusions where the mouth is. A diagnostic black line (face paint or tattoo) runs down the figure's cheek.
The gloss gives "Ecatl," but the visuals suggest "Ehecatl." This is a recurring phenomenon across the glyphs from many manuscripts. Perhaps the reduplication was barely noticeable in spoken speech.
Ehecatl is a noun in Nahuatl that means wind, and the word was also a proper name for the divine force of the wind. In turn, this divinity was an aspect of the creator (with Quetzalcoatl associations) and with the night. This representation of Ehecatl (which was also a name borne by some humans, given that it was a day sign in the calendar), was apparently how humans saw the divine force associated with the wind.
The second sun on the Aztec sun stone has a much more elaborate representation of the wind; this epoch was ruled by Quetzalcoatl. The second sun was destroyed by hurricanes and the people were turned into monkeys.
For other images of Ehecatl and more information about his shape and that of Quetzalcoatl, see Mexicolore. One of the pre-Columbian statues devoted to the wind gives him a monkey's body but the same buccal mask (large point above the mouth or beak) as we see in this glyph. A type of hummingbird has the name ecahuitzilin, which shows another possible connection between the divine force associated with the wind and birds. But the ecahuitzilin seems to have coloring that is different from the visual in this glyph.
Gabrielle Vail and Christine Hernández (Re-Creating Primordial Time, 2013, ) describe Ehecatl as the wind aspect of Quetzalcoatl, and they note that Ehecatl "wears a buccal (duck) mask through which to blow wind." That the "beak" may have been perceived as a blowing device is supported by the glyph for Pitztli (below).
wind, air, breath, aire, viento, aliento
eca(tl), breath/air, https://nahuatl.wired-humanities.org/content/ecatl
eheca(tl)/Ehecatl, divine force/deity, wind, https://nahuatl.wired-humanities.org/content/ehecatl
Matrícula de Huexotzinco, folio 484r, World Digital Library, https://www.loc.gov/resource/gdcwdl.wdl_15282/?sp=47&st=image
This manuscript is hosted by the Library of Congress and the World Digital Library; used here with the Creative Commons, “Attribution-NonCommercial-ShareAlike 3.0 License” (CC-BY-NC-SAq 3.0).