Yaotzin.

Headword: 
Yaotzin.
Principal English Translation: 

the name of a deity; also, a personal name; the name of a Chichimec ruler of Huexotla (Huejutla) (see the Florentine Codex); he was called a "tecutli" (Lord Enemy)

Orthographic Variants: 
Iautzin, Iaotzin, Yautzin
Attestations from sources in English: 

Auh in titlacaoan, no qujtocaiotiaia tezcatlipuca, moiocoiatzi, iaotzi, necoc iautl, neҫaoalpilli = And Titlacauan they also named Tezcatlipoca, and Moiocoiatzin, Yaotzin, Necoc iaotl, and Neҫaualpilli (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 3 -- The Origin of the Gods, Part IV, 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, 1978), 12.

Injc chiquacen tlatoanj itoca iautzin tecutli in tlatocat vmpoalxiujtl ioan caxtolxiujtl ipan exiujtl = The sixth ruler was named Iaotzin tecutli; he ruled fifty-eight years. (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 8 -- Kings and Lords, no. 14, Part IX, 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), 13.

Attestations from sources in Spanish: 

Yautzin Tecuhtli: "Señor enemigo." En las pinturas se añade una piedra (tetl), como ideograma del prefijo te-, para indicar que es enemigo "de alguien".
Víctor M. Castillo F., "Relación Tepepulca de los señores de México Tenochtitlan y de Acolhuacan," Estudios de Cultura Náhuatl 11 (1974), 183–225, y ver la pág. 193.