Principal English Translation: 

White-faced Ibis (see Hunn in attestations)

Orthographic Variants: 
Acacalotl (capitalized for being a species)
Alonso de Molina: 

acacalotl. cueruo marino. Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 1r. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

Ā-CĀCĀLŌ-TL, literally, “water raven,” White-faced Ibis (Plegadis chihi). The Florentine Codex, 43, gives: Acacalotl: “It is black – a waterfowl, an eater of water life. The legs are long, very long, black; it has a sharp curved bill.” Martin del Campo identified this as the Jabiru (Jabiru mycteria) but noted that Santamaría indicated that the term acacalote applied to Plegadis guarauna, an obsolete Latin name for the White-faced Ibis. This latter identification is far more likely than the Jabiru, as the Jabiru nests rarely in a restricted area of the coastal marshes from eastern Tabasco east, while the White-faced Ibis is a fairly common nesting species across the highlands of central Mexico (Howell and Webb). Also, the ibis fits the description much more closely than the Jabiru, in particular, its curved beak.
E. S. Hunn, "The Aztec Fascination with Birds: Deciphering Sixteenth-Century Sources," unpublished manuscript (Petaluma, California, 2022), cited here with permission. Hunn also cites: 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 Undécimo 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, Numero 1. Mexico, D.F., 1947; and, Steven N. G. Howell and Sophie Webb. A Guide to the Birds of Mexico and Northern Central America (Oxford, New York, Tokyo: Oxford University Press, 1995, 147, 149).