[6] Techichis were larger than modern Chihuahuas, but were bred into the smaller, lighter dog known today by the Aztecs.

[3][7] The first European to encounter the dog breed was the Spanish explorer Francisco Hernandez, who reported its existence in 1578.

[8][9] To the Toltecs, Techichis were believed to have supernatural powers, such as seeing into the future, and they were often sacrificed so they could guide their owners in the afterlife.

[10] Like the Toltecs, the Aztecs also believed that Techichis could guide human souls after death, and that they could guard pyramids if buried underneath them.

[11] Several pre-Columbian artefacts have been discovered depicting the dogs, including wheeled toys[12] and effigy pots.