Harut and Marut
Muhammad's companions say that Harut and Marut have been angels in heaven who were outraged by human's sin. God then made a bet with the angels, that they wouldn't be better, if they lived on earth with human urges. They agreed but actually sinned on earth and so they were not allowed to return to heaven. Further, they have to choose their punishment, either in this world or in hell. They choose earth, and so they became (fallen) angels tempting people into sorcery.