I have only ever come across references to Tlatlacateculo ("Owl Men") once. And I gave a brief summary in this topic titled Did ancient military's have "elite" units like the SAS or SEAL Team Six of today?. In essence, though, Tlatlacateculo likely used a combination of prayer, totems, and knowledge of plants and animals to cure, kill, or torment (usually in their dreams) other people including other witches. I'm basing this assumption on more recent ethnographic work on historic and contemporary Nahua witches in Mexico (Knab 1995). The shapeshifting, or nagual, aspect factors into the dream world. Each person has a nagual that is linked to them that lives in the dream world. What happens to one, happens to the other. So witches can use their nagual in their dreams to harm or help the naguals of others while they are dreaming. This might even be considered a form of psychological warfare if someone begins to become sick or has insomnia and begins to believe that someone is attacking them in their sleep. But to repeat, I am making these speculations based on more recent ethnographic work.

---

Knab, Timothy A. 1995 A war of witches: a journey into the underworld of the contemporary Aztecs. Harper Collins, San Francisco.

The owl men of Mesoamerica are definitely one of the more sinister types of traditions, particularly in central Mexico rather than the other inhabitants of the Yucatan. I will be dividing what sorcery and magic was known within the Aztec Triple Alliance territories and within the perimeters of the Mayans as well.

Aztecs/Nahuas:

Just as you mentioned the owl men were sent against Spanish allies of Hernán Cortés, they were specifically planned out by Cuauhtemoc. Here is a translation from original Nahuatl text of when this happened (Translated by James Lockhart) for context:

And then the ruler Quauhtemoctzin...took a great warrior named Tlapaltecatl opochtzin, whose home was in Coatlan, and outfitted him, dressing him in a quetzal-owl costume. That had been the device of Ahuitzotl. Quauhtemoctzin said..."Let us make an experiment to see if we can escape this danger in which we find ourselves. Let one of the most valiant among us come and don the arms and insignia that belonged to my father Ahuitzotzin."

"Put it on; fight in it, and you will kill some people. Let our enemies see this costume; it could be that they will be frightened by seeing it." When they dressed him in it, he appeared a frightening spectacle. "...Let him wear it, let him die in it. Let him dazzle people with it, let him show them something; let our enemies see and admire it.”

They gave him the darts of the devil [Huitzilopochtli] , darts of wooden rods with flint tips. And the reason they did this was that it was as though the fate of the rulers of the Mexica was being determined.^(1)

Given this context, we know that it has previosuoly been in use by Ahuizotl, the father of Cuauhtemoc, had been used. In this case, the quetzal-owl "costume" foretold if the Aztecs should continue fighting. By winning a skirmish, it would mean the gods permit war to continue. However, despite the Spanish being 'defeated' here, Cuauhtemoc was said to prefer negotiations instead, having almost no nobles. Sahagún was one of the ethnographers who often labeled deities as demons or the 'devil.'

Moving forward, owl-men were thought to be tlacatecolotl, meaning (horned) owl-man, sorcerer, or a demon. In Nahua religion, Mictlantecuhtli, lord of Mictlan, is thought to be responsible for owls. Luchazas, or screeching owls, were more common with Mictlantecuhtli instead. However, animals such as owls were related to him, but another deity, Tezcatlipoca, who was attributed for practice of sorcery (especially at night). Tezcatlipoca is a deity that is known to have many aspects of their deities, such as Chalchiuhtecolotl, thought to mean "Precious (Horned) Owl", who is known for being active at night and associated with sorcery as well.

Similarly, the nahualli, or naguals were seen as animal spirits, sorcerer, or a shape-shifters. Unlike the similar tlatlacatecoloh (plural), naguals could either do good or bad deeds. The tlatlacatecoloh were only thought to bring misfortune at night, using sorcery to bring disease and death instead of a balanced approach. Hence why tlacatecolotl could mean "a possessed person" too.

Spells and magic were practiced for either benefits or destruction. It was up to whoever practiced it to bring fortune or misfortune. Just as Bernardino de Sahagún mentions in the same text of nahualli or naguals:

The good sorcerer [is] a caretaker, a man of discretion, a guardian. Astute, he is keen, careful, helpful; he never harms anyone. The bad sorcerer [is] a doer [of evil], an enchanter. He bewitches women; he deranges, deludes people; he casts spells over them; he charms them; he enchants them; he causes them to be possessed. He deceives people; he confounds them...

Just as there may be good and evil in Abrahamic religions, the Nahuas believed in order and chaos. Here, Tezcatlipoca may be seen as a deity of misfortune. But why is he even viewed as one of the 'main' deities then? That is where the 'chaos' plays, while the 'order' would be worship and respect to the forces of nature, here Tezcatlipoca representing disease, plague, famine, and even sorcery as a natural force.

Additionally, according to the tonalpohualli, the ritualistic Mexica calendar used for things such as determines significance on birth days. For example, people born on days like Ce Quiahuitl, 1 Rain, and Ce Ehecatl, 1 Wind, allowed one to possess these abilities. People of higher status and nobility could transform into large beasts while people of lesser roles could transform into smaller beings.^([2] [3]) but do note that there are various other forms of 'witches' and 'sorcerers' besides nahualli and tlatlacatecoloh*.*

For further reading, I suggest reading this amazing page about sorcery in Mesoamerica, including Nahuas and Mayans by Mexicolore for a good understanding. Also, read this excellent answer concerning Nahua 'witches' by u/400-Rabbits.

​

Mayans:

Similar to the Nahualli of the Nahuas, the Mayans, mostly during the Classical Mayan period, believed in wáay (pl. Wayob') where 'destinies' or images were shown in dreams. Though may be labeled as sorcery, it was spiritually significant to Mayans, but may be interpreted as resembling sorcery as well. Wáay may be translated as a witch, sorcerer, to bewitch or even fantasy and fright in Yucatec Mayan.'

It may be less information, but the Mayans also did believe in many similar beliefs as the neighboring Nahuas. Especially about bats and owls, dieties such as Camazotz in K'iche' Maya and Itzamna'' relating to some sorcery. Though, it is all unclear due to recorded accounts not present as much as Nahua ones. The most it can be is a historian like Diego de Landa, but even he was responsible for destruction of Mayan text as a Spanish bishop.

---

^(1) Bernardino de Sahagún, Códice Florentino: Historia general de las cosas de Nueva España

^(2) Nutini, Hugo and John Roberts 1993 Bloodsucking Witchcraft: An Epistemological Study of Anthropomorphic Supernaturalism

^(3) Jeremy D. Coltman, Mexicolore: Witchcraft and Sorcery in Ancient Mexico

(I'm only a grad student trying to pretend I don't have another semester ahead of me. As a disclaimer, I use Nahuatl and Aztec interchangeably).

If you're interested in why an owl would be portrayed as an active agent of death, follow me.

Following Leon Garcia Garagarza's 2020 entry, we can see his interpretation of "Owl Men" that includes physiological functions of ornithology and how that could influence human society in Mesoamerica. In communities that are more engaged with traditional expressions that stem back to the time of or before the Spanish invasion of Mesoamerica, of current Mexico, owls have been associated with impending death. Although they herald death, they weren't explicitly omens of evil in Aztec, Nahuatl, Mexica culture, merely death as a matter of fact. In more contemporary days it's become more sinister in implication.

Indeed, a commonly heard Mexican proverb states, “Cuando el teco- lote canta, el indio muere” (“When the owl sings, the Indian dies”). Growing up in Mexico City, this proverb always fascinated me. “Why is it,” I would ask myself as a child, “that the song of the owl—those mournful notes that enchanted me every time I heard them issuing from the canopy of the ash tree just outside my window—should only bring death to an indio, and not to me?” (Garagarza, 2020: 456)

Indeed, the bird was often considered the animal disguise—or nahualli—of a murderous sorcerer: known precisely as a man-owl (tlacatecolotl). So, people heard the owl, and died. In that sense, the fatality of the owl’s omen seems to be wholly dependent on the predisposition to believe in it, on having the cultural repertoire that makes a bird’s call an intelligible prophecy of death. Absent this repertoire, the owl becomes just a bird whose hoots and cries are meaningless and, therefore, harmless: the indifferent owl of the modern citizen (Garagarza, 2020: 456)

Garagarza's anthropologist side comes through here in evaluating cultural elements of his home nation that strike close to his heart. Sustaining a belief in the bird as a crier of omen enables the ability to interpret its call as deadly, and vice versa, hearing the cry that sounds like an animal-spirit almost speaking human words sustains a belief that the bird is a spiritual power. In further reading -- not just in Garagarza's pieces -- it is evident that Aztec culture and evidenced through its writing system is filled with descriptions of animals as spiritual beings. This should let you begin to see why the dressing of shamans or priests as owls would be a powerful symbolic gesture. Whether or not people actually did this against Cortes is not the point of this post or the quoted author.

The proverb reflects, moreover, a fundamental aspect of the Mesoamerican animistic worldview, where owls, like other remarkable creatures, are perceived mainly as tetzahuitl—that is, as embodied omens, or communicative agents of the sacred that demand interpretation and ritual reciprocity. The Nahua tetzahuitl—like all omens—are more than symbols; they are living and intelligible signs of a semiotic process that links the human and the divine in a constant phenomenological dialogue. Mediated by creatures and other phenomena, omens articulate the verdict of a particular deity as to the fate of the person or the community that engages with them, and so omens establish a dialectics of divination, of interpretation oriented toward the future. This is a pivotal consideration in any study of Mesoamerican animal lore (Garagarza, 2020: 456).

Animals as zoomorphic entities is a pillar of the Aztec faith structure. The sanctity of owls is one of many other examples of how humans could become more than flesh, of how animals can become more than flesh. Combined, the owl-man is greater than the sum of his parts, he's a living spirit connecting the ethereal to terra and society. As you ask in your prompt, what other examples are there of ritual zoomorphism? Well, even within the owl caste there is more than one group, there's actually two which hopefully reveals to you how intentional Aztecs were with their spiritual interpretations. For the correct receiving and deciphering of omens, there are two distinctions of owls in Nahuatl terms.

For their part … the ancient Nahuas also recognized two basic types of owls, a categorization semantically expressed by the difrasismo (López Austin 2003) in tecolotl, in chiquatli (“the owl, the barn owl”). Through their apparent morphological and behavioral similarities, the Nahuas knew that both birds were related as tetzahuiani (ominous) manifestations of the lords of the underworld—a principle represented by the phrase quimotetzahuiaia in chiquatli in tecolotl: “people were ‘omened’ (spooked, terrified) by the barn owl, the owl” (Sahagún 1979, bk. 1: fol. 4)(Garagarza, 2020: 457)

Except for the persistent depiction in Mesoamerican codices of the tecolotl as an eared owl, the distinction between the tecolotl and the chiquatli was based not so much on the visual, morphological characteristics of each species, but rather on the distinctive character of the calls of each bird (Garagarza, 2020: 459)

Physical appearances aren't nearly as important when the subject matter is a stealthily flying bird of the night that can't easily be seen with nothing more than moonlight or torchlight. But why would these birds become symbols of death? Is it because they have big eyes and can twist their necks? Possibly, but there's an even more interesting linguistic and cultural reason that factors into their designation as a spiritual power of doom in our mortal plane. The bird's call is transcribed and repeated as "tecolo, o, o, tecolo, o, o" -- for reading comprehension's sake this is similar to the American English call of "hoo-hoo, h'h'h'HOO" used generally for owls -- is an animal sound that sounds close to an actual Nahuatl verb.

The tecolotl received both its name and its destructive character as a function of the intelligible nature of its call, for the syllables “tecolo, o, o, tecolo, o, o” can be construed to signify the Nahuatl phrase, “Harm people, harm people” (indefinite personal object prefix te + verb coloa: “to make crooked”=“to harm”). This etymological identification of the bird also explained the title of the tecolotl’s human nahualli, the deadly sorcerer known as tlacatecolotl, whose only objective was to harm his or her target. Reciprocally, the tecolotl owl was often perceived as the avian metamorphosis of a human form of tlacatecolotl sorcerer who had transformed himself into that bird to inflict death, illness, and destruction (Garagarza, 2020: 465)

Birds are seen as beings that "manifest the superhuman ability"(Garagarza, 2020: 459) to do more than communicate, they can literally travel into the sky or the depths of caves. A being that can talk, fly to heaven AND to hell? - that must surely be a servant of the gods. A priest wearing an outfit decorated in the feathers of a sacred bird, or wielding a tool with feathers, could be seen as a conduit of spiritual dimensions and therefor worthy of awe, respect, and fear. Priests appropriating the powers of animals extended far and beyond these owl-men, examples of such spiritual "zoomorphic omens"(Garagarza, 2020: 460) grow into proportions way outside the scale of this post, with three bird groups specifically mentioned (which includes the tecolotl and the chiquatli), 10 other animals alluded to, and swathes more of creatures.

Interestingly, the noun chichtli also named a peculiar clay whistle that actually reproduced the eerie screams of the chiquatli. Some surviving Aztec chichtli whistles are carved in the shape of owls(Lopez, 2020: 466)

...the chichtli whistle sounded during the Xalaquia ceremony confirms the role of the chiquatli owl as the omen of the Lord of Mictlan, whose voiced “message” preceded the capture of its unfortunate target’s tonalli soul and fatally delivered him or her to the clutches of death. Book 5 of the Florentine Codex expressly states the identity of the bird as “the messenger, the envoy of the Lord of Death, of the Lady of the Dead” (“intitlan intlaioal, in mjctlan tecutli: yoan mjctecacioatl”) (Sahagún 1979, bk. 5, chap. 5:163) (Garagarza, 2020:466)

This is the closest to connecting to your question, OP. As an apex predator that flies silently in night sky, with a cry that seemingly announces "harm" to anyone that is unfortunate enough to be under its flight path, a priest invoking this animal could theoretically summon death to their target (or the opposing army) or instill a sense of confidence or fear (depending on which side you are on of the priests). This belief of the power in priests was systematically reinforced through cultural values that placed these two types of owls as foretellers of death. There is often the erroneous idea that animalistic spiritualisms aren't codified, yet the Aztec temples and religious monuments are carved with logograms and syllabic signs that reveal a system that sprawled well beyond one city and into the dominion.

Follow to next comment...