Andean sky-watching reads two kinds of constellation. There are the star-to-star figures familiar everywhere, and there are the dark cloud constellations, animal shapes read from the dust lanes that block the light of the Milky Way. The second kind is rare in the world and the Andes is its best documented home.
Yacana, the llama, is the largest of them, lying along the Milky Way with two bright stars in Centaurus as its eyes. Beside it is a smaller shape read as its offspring. The set continues with Machacuay the serpent, Hanp'atu the toad, Yutu the tinamou and Atoq the fox, and their rising and setting order through the year is tied to the agricultural and herding calendar.
An account recorded in the Huarochiri manuscript, the one substantial religious text written in Quechua in the colonial period, has Yacana come down at midnight to drink from a spring, and says that a man on whom it descends will be fortunate. It is also said that if it did not drink, the world would flood.
The dark constellations were reported by Spanish observers who did not understand what they were being shown and recorded them as superstition about black patches. They were properly documented only in the twentieth century, and the fullest account is Gary Urton's fieldwork in the community of Misminay, which established that the system was still in use.