Principal English Translation: 

scorpion(s) (see Molina)

Orthographic Variants: 
culotl, collotl
Alonso de Molina: 

colotl. alacran.
Alonso de Molina, Vocabulario en lengua castellana y mexicana y mexicana y castellana, 1571, part 2, Nahuatl to Spanish, f. 24r. col. 2. Thanks to Joe Campbell for providing the transcription.

Attestations from sources in English: 

yn yehuatl yn oçomatzin teuhctli, iuh mitohua nahualli catca moch quinnotzaya yn tocame yn petlaçolcohuatl yn cohuatl yn tzinaca yn collotl, ynic mochtin quinnahuatiaya quipiaya yn ichpoch miyahuaxihuitl = Oçomatzin teuhctli was said to be a sorcerer. He summoned all manner of spiders, centipedes, snakes, bats, and scorpions; he commanded them all to guard his daughter, Miyahuaxihuitl. (central Mexico, early seventeenth century)
Codex Chimalpahin: Society and Politics in Mexico Tenochtitlan, Tlatelolco, Culhuacan, and Other Nahuatl Altepetl in Central Mexico; The Nahuatl and Spanish Annals and Accounts Collected and Recorded by don Domingo de San Antón Muñón Chimalpahin Quauhtlehuanitzin, eds. and transl. Arthur J. O. Anderson and Susan Schroeder (Norman: University of Oklahoma Press, 1997), vol. 1, 120–121.

cocoloh (the reduplicative plural form)
Antonio Rincón, Arte mexicana: Vocbulario breve, que solamente contiene todas las dicciones ue en esta arte se traen por exemplos (1595), 5r.

Citlalcolotl. = The Scorpion Stars (central Mexico, sixteenth century)
Fr. Bernardino de Sahagún, Florentine Codex: General History of the Things of New Spain; Book 7 -- The Sun, Moon, and Stars, and the Binding of the Venus, No. 14, Part VIII, 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, 1961), 13.

culotlalpili, ic motzinapanticac = around his loins is bound a cloth with a scorpion design
Fray Bernardino de Sahagún, Primeros Memoriales, ed. Thelma D. Sullivan, et al. (Norman: University of Oklahoma Press, 1997), 97.