Itzcuintli's patron is Mictlantecuhtli, the skeletal lord of Mictlan, a pairing of exact fit between day sign and governing deity, since the dog's funerary role of guiding the dead directly serves the underworld lord's own domain, one of the clearest and least ambiguous patron matches in the whole twenty sign count. Its direction is north, shared with Ehecatl, Miquiztli, Ocelotl and Tecpatl in the four direction rotation's recurring second station. Itzcuintli is not a year bearer, sitting two places on from Calli at three and three short of Tochtli at eight, outside the spacing that defines the four year bearer signs. Mictlantecuhtli's patronage here as day sign governor is a separate office from his standing as the fifth and central of the nine Lords of the Night, a numeric placement earlier commentary on the night lord sequence has read as fitting for the death lord to occupy the rotation's midpoint, so the underworld lord holds two distinct posts within the tonalpohualli's several registers, both concerned with death and the underworld but assigned independently by the surviving codices rather than treated as a single combined role.
The Legend of the Five Suns names Mictlantecuhtli as the keeper who very nearly prevented Quetzalcoatl from carrying the bones of earlier human generations out of Mictlan, a myth that makes the underworld lord's patronage of the dog, the animal whose whole role is to help a soul complete that same crossing, read as a fittingly watchful pairing.