tlahuipochtli.

tlahuipochtin = those who walked about at night "spitting fire and causing madness, sickness, or death in their victims"
Louise M. Burkhart, Before Guadalupe: The Virgin Mary in Early Colonial Nahuatl Literature, Institute for Mesoamerican Studies Monograph 13 (Albany: University at Albany, 2001), 26, citing Bautista 1600:112 r. and v.

"nanahualti, tlahuipuchtin" = sorcerers
Florentine Codex, Book 5, Chapter 27; cited by G. Baudot, "Dieu et la Diable en Nahuatl," in Marie-Cécile Bénassy-Berling, ‎Jean-Pierre Clément, ‎Alain Milhou, eds., Langues et cultures en Amérique espagnole coloniale, 1993, 155.

In reference to the tlahuelpuchi/tlahuepoche or “fiery red smoke” in Tlaxcala and the Sierra Poblana, Edgar Martín del Campo writes: "The term tlauipuchin appears only on the Spanish side of Molina’s Nahuatl-Spanish dictionary, where it is simply 'another witch.' My translation is based on Carochi’s transcription of the plural form tlahuìpochtin, which Carochi translates into bruxos or 'witches'; Horacio Carochi, Grammar of the Mexican Language with an Explanation of Its Adverbs, trans. J. Lockhart ([1645]; repr., Stanford, CA: Stanford University Press, 2001). Carochi’s orthography is problematic because of its morphological ambiguity. Karttunen suggests that the long /a/ is the “discrepancy” (Frances Karttunen, An Analytical Dictionary of Nahuatl [Austin: University of Texas Press, 1983], 270), in which case the word would be derived from the root /tlahuih-/, “curse.” I propose that the discrepancy is actually the 'saltillo' coda in the second syllable; without this, the /tlahu(i)-/ root would indicate 'red ochre/firelight' (270). This would buttress the association of the tlahuepoche with fiery flight and breath, which has been described since the Early Colonial period through authors such as Fray Juan Bautista, Juan de Torquemada, and the more skeptical author of the Codex Carolina" citing Alfredo López Austin, "Cuarenta clases de magos del mundo náhuatl," in Estudios de Cultura Náhuatl 7 (1967), 93.

"Tlahuelpuchi" is a term for a witch (bruja) well known among Nahuas of Tlaxcala, especially, where infant death was often attributed to the witch sucking the blood of the baby.
See Hugo Nutini, Todos Santos in Rural Tlaxcala, 1988, 134.

Another (non-academic) source says that the practice of putting this cause of death attributed to a tlahuelpuchi on death certificates stopped in 1954, because a law was passed saying that all such deaths needed to be investigated, and people did not wish to have the government meddling in their lives.
https://mexicounexplained.com/vampire-witches-central-mexico/

tlahuihpochtli = "Magicien ou plutôt magicienne ou sorcière suceuse de sang." (a magician, sorceress, or blood-sucking witch)
Gran Diccionario Náhuatl, citing A. Wimmer 2004, https://gdn.iib.unam.mx/diccionario/tlahuipochtli/68355. Translated here to English by Stephanie Wood.