Gjallarhorn

In Norse mythology, Gjallarhorn (Old Norse "yelling horn" or "the loud sounding horn") is a mystical horn blown at the onset of Ragnarök associated with the god Heimdallr and the wise being Mímir. Gjallarhorn is attested in the Poetic Edda, compiled in the 13th century from earlier traditional material, and the Prose Edda, written in the 13th century by Snorri Sturluson.