Snowy Egret, a bird (see Hunn, attestations); also, a term for a heron-feather headdress (see Molina and attestations)
AZTA-TL, Snowy Egret (Egretta thula) [FC: 28 Aztatl] “It is also called teoaztatl. It is white, very white…. It is long-necked, stringy, curved. The bill is pointed, long and pointed, black. The legs are very long, stringy, stilt-like, black. The tail is stubby.” I agree with Martin del Campo that this is the Snowy Egret, though the Great Egret (Egretta alba) is quite similar, but with a yellow bill.
Naztauh, nomecaxicol. Quitoznequi: inic onechtequimacac in altepetl: ic in itlacauh oninochiuh intla niquitlacoz, intla itla ic nicouitiliz: nictzactiaz. = My heron-feather headdress, my jacket of ropes. This means: When the city gives me a responsibility I become a slave. If I hurt the city in some way, if I endanger it, I shall be put in jail.
aztatl = egret (late sixteenth-century, Tetzcoco?)
auh yoan yn jquac y, tlaacopiloaia: auh ynaca oc concholotiaia, yn iqueztepol malli: yoan mecaxicolli, aztapalactontli itech pilcac = Moreover, at this same time he put up [on the point of the pole], so that it hung—having removed the [remaining] flesh—the thigh bone of the captive, and suspended with it the sleeveless knotted cord jacket and a small spray of heron feathers. (16th century, Mexico City)