cozcacuauhtli.

COZCA-CUĀUH-TLI, literally, “necklace/yellow eagle/hawk,” Crested Caracara (Caracara cheriway) [FC: 42 Cozcaquauhtli] “It is smoky. The wings are curved, resembling an eagle’s. The bill is curved.” Martin del Campo identified this bird as the King Vulture (Sarcoramphus papa). However, I can see no reason for that conclusion based either on the name or the Codex description. The attributive would mean “necklace/jewel/ornament” if the vowel “o” were long; yellow if short. A more likely interpretation is that the bird in question is the Crested Caracara (Caracara cheriway), as it is said to resemble the Laughing Falcon, see HUAC-TLI.
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 11 – Earthly Things, no. 14, Part XII, eds. and transl. Arthur J. O. Anderson and Charles E. Dibble (Santa Fe and Salt Lake City: School of American Research and the University of Utah, 1963); Rafael Martín del Campo, “Ensayo de interpretación del Libro Undecimo de la Historia General de las Cosas de Nueva España de Fray Bernardino de Sahagún – 11 Las Aves (1),” Anales del Instituto de Biología Tomo XI, Núm. 1 (México, D.F., 1940); and, with quotation selections, synthesis, and analysis here also appearing in E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript, 2022, cited here with permission.

The name glyph for the cozcacuauhtli in the Codex Quetzalecatzin shows a red protrusion above the beak and spiky feathers on its head.

axcan ypan xapato mo poa nahui cali tecpatl cali tochi acatl chihuitl cahuitl zipatli= ehecatl= cali= cuespali= cohuatl= miquistli= masatl= tochi= atl= iscuintli= osomatl= minali= acatl= ocelotl= quautli= coscaquautli= olin= tecpatl= quiahuitl= chochitl = ahoy en éste día sábado que se cuenta cuatro casa. Pedernal, Casa, Consejo, Caña, signos de los años en el Tiempo estos cuatro signos se cuentan. Lagarto, Mono, Viento, Yerba tocida, Casa, Caña, Lagartija, Tigre, Culebra, Aguila, Muerte, Aguila de collar, Venado, Movimiento, Conejo, Pedernal, Agua, Lluvia, Perro, Flor (Estado de Hidalgo, ca. 1722?)
Rocío Cortés, El "nahuatlato Alvarado" y el Tlalamatl Huauhquilpan: Mecanismos de la memoria colectiva de una comunidad indígena (New York: Hispanic Seminary of Medieval Studies, Colonial Spanish American Series, 2011), 34, 46-47.