[1] It is not entirely clear—from an Imāmī perspective—what Dhū’l-Qarnayn's “horns” actually were. WikiShia has this to say about it: Concrete meanings: the first group of such views provide concrete grounds for the appellation, such him having horns and something similar. For example, some people believed that he had two excrescences on his forehead which were similar to horns, or that his crown was decorated with two horns, or his people had broken the two sides of his head, or he had two strings of braided hair. Abstract meanings: the second group of such views provide abstract grounds for the appellation associated with other meanings of the word, “qarn”. For example, during his life, two generations of people disappeared, or he reigned both in Iran and Rome, or he found his way both to the eastern and the western parts of the world, or he was a nobleman both through his father and his mother, or that he saw in a dream that he held two sides of the sun, or he was endowed with the knowledge of the exterior and the interior. Refer to this: https://en.wikishia.net/view/Dhu_l-Qarnayn.