According to the folklore of Navarre, a Basque-speaking autonomous community in northeastern Spain, Ujanko is the personification of the year, a creature with a single huge eye on his face, two rotten teeth in his mouth, ten-fingered hands, and with a body completely covered in red fur and a multitude (one for each day of the year) of sparkling red eyes that disappear one by one each day until they all reappear on New Year's Eve. According to the story around Salinas de Oro, having regained all of its eyes, Ujanko is able to see through children and know exactly whether they have been obedient or not, and based on this, punish or reward them with a New Year's gift (432: p.95; 1657: p.140).

Ujanko is close to a number of other similar creatures from different regions of Spain: Olentzaro from the Basque Country, Hombre de los ojos from Cabezuela del Valle in Extremadura, Home dels Nassos from Catalonia. And also Ujanko naturally resembles the giant Argus from ancient Greek myths.