Wayob is the plural form of way (or uay), a Maya word with a basic meaning of 'sleep(ing)', but which in Yucatec Maya is a term specifically denoting the Mesoamerican nagual, that is, a person who can transform into an animal while asleep in order to do harm, or else the resulting animal transformation itself. Already in Classic Mayan belief, way animals, identifiable by a special hieroglyph, had an important role to play.
In Yucatec ethnography, the animal transformation involved is usually a common domestic or domesticated animal, but may also be a ghost or apparition, for example 'a creature with wings of straw mats'. Moreover, in the 16th century, wild animals such as jaguar and grey fox are mentioned as animal shapes of the sorcerer, together with the ah uaay xibalba or 'underworld transformer'. Some sort of 'devil's pact' seems to be implied. The Yucatec way has its counterparts among other Mayan groups. In Tzotzil ethnography, the way (here called wayohel) is more often an animal companion and refers not only to domestic animals, but also to igneous powers such as meteor and lightning. In Tzeltal Cancuc, the nagual animal companion is considered a 'caster of disease'. Other names found are: Lab, labil, wayixelal or vayijelal, way and wayxel or wayjel.