See an image that represents opochtli in the Visual Lexicon of Aztec Hieroglyphs, ed. Stephanie Wood (Eugene, Ore.: Wired Humanities, 2020-present).
Opochtli was the patron deity of the Atlaca, those specializing in fishing and other aquatic subsistence activities, and was credited with the invention of the fishing net, the atlatl (spear-thrower), the minacachalli, the three-pronged fishing harpoon, the pole for propelling canoes, and the snare for catching aquatic birds. (Sahagún 1970: 37).
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 103.
The Atlcahualo (ceasing of water, rain), was the name of the first festival of the year. The ceremonies practiced at this time were meant to ensure the rains would come again. They included the sacrifice of small children, preferably children with two cowlicks in their hair, considered like whirlpools, and sometimes called "banderas humanas." The children would be sacrificed atop hills or mountains associated with the tlaloque (Tláloc deities). Other tlaloque are Nappatecuhtli, Opochtli, Tomiyauhtecuhtli (one of the four hundred rabbits that were deities of pulque), and the tepictoton, small legless figures.
Bernardo Ortiz de Montellano, "Las hierbas de Tláloc," Estudios de cultura náhuatl 14 (1980), 287–314, see p. 290.
Opochtli, one of the tlaloque, was the patron of the people of the boats and the fishing people. During celebrations of this deity, tobacco, copalli, and yauhtli were made in offerings.
Bernardo Ortiz de Montellano, "Las hierbas de Tláloc," Estudios de cultura náhuatl 14 (1980), 287–314, see p. 292.njman oiauh, opuchmaie, qujn iehoatl qujmamimictia, qujmaiauj, qujtentimaiauj: injn ipan mixeoaia in opuchtli = then came one who was left-handed. He then wounded his arm and threw him flat upon the surface. This one appeared as [the divine force] Opochtli. (16th century, Mexico City)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 2—The Ceremonies, No. 14, Part III, 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, 1951), 51.