This article examines the relationship between ritual specialists, nanahualtin or nahualistas (pl.) and nahualli or nahual (sing.), and healing practices, adding context to the social roles they fulfilled and the range of feats they performed. The cases examined here reveal that nanahualtin operated as intellectuals in their communities because of their ability to control animals, prognosticate, and heal or harm individuals at will. Some nanahualtin shapeshifted from humans to animals while others possessed animal companions. The elevated status of nanahualtin led commoners to seek their advice, which conflicted with the established orthodoxy of the Catholic Church. Because clergymen championed the sacraments as the best way to access the divine, non-orthodox rituals performed in mountains, rivers, and caves were derided as idolatrous devil worship.

The 11 criminal and Mexican Inquisition cases examined here range from 1599 to 1801. Two seventeenth-century cases (1678 and 1685) and one eighteenth-century case (1701) contain Nahuatl phrases and testimonies from Chiapas and Tlaxcala, respectively. The cases from Chiapas demonstrate the use of Nahuatl as a vehicular language outside the central valley of Mexico. This article examines the gender of the animals into which ritual specialists transformed as an emergent category from trial records, which provides insight into Catholic officials’ understanding of the nahualli. Last, this study notes social divisions between rural and urban clergy regarding the power of nanahualtin and the efficacy of their magic.