Kueyen or kuyen is the name that is given to the moon in Mapuche

Mapuche

The Mapuche are a group of indigenous inhabitants of south-central Chile and southwestern Argentina. They constitute a wide-ranging ethnicity composed of various groups who shared a common social, religious and economic structure, as well as a common linguistic heritage. Their influence extended...

 mythology. She is the principal wangulen spirit. Kueyen governs the others wangulen spirits (spirits of the stars). Kueyen is married Antu

Antu (mapuche mythology)

Antu is the name that is designated in the Mapuche, the principal pillan spirit. Antü is the most powerful Pillan, who governs the others pillans. In the Mapuche mythology, Antu is the Sun, and is married with Kueyen a Wangulen spirit that represents the moon....

 (the Pillan

Pillan

The Pillan is a powerful and respected male spirit in Mapuche mythology....

 spirit that represents the sun).

Mistakenly, Kueyen is also sometimes known by the name of Anchimallen (a name that makes reference to another class of mythological creatures).