In Norse myth, Mani is the personification of the moon, son of Mundilfari and brother of Sol, the sun. At night he rides a chariot pulled by horses through the sky, and determines its waxing and waning. Mani is chased by the wolf Hati ("hate"). Whenever the wolf managed to catch the moon, a lunar eclipse would take place. This caused great consternation, and by making a lot of noise people tried to scare the wolf away. A man named Vidfinn had two children named Hjuki and Bil. He sent them to the well Byrgir to fetch a cask of water. When Mani saw the two children he took them away with him to the moon. The two children, together with their cask and pole, can be seen on the face of the moon (the moon spots). In some accounts, Mani himself kidnapped two humans, a girl named Bil (Waning) and a boy named Hiuki (Waxing), children of Vidfinn, as they were leaving a well called Byrgir. Thereafter he forced them to travel with him, as could be seen in the moon's phases.
The Vikings believed that when the two wolves caught up with the sun and moon, they would swallow them and all the stars would disappear from the sky. It would be a signal that Ragnarok, the battle between the forces of good and the forces of evil, was about to begin, and that the end of the world was at hand.