Floats the Raven Banner O’er Us
Up Helly Aa's traditional raven banner catching fire above the galley. Apparently ravens are associated with the Norse God Odin, and the raven symbol was often displayed on the war flags of Viking chieftains.
"As Odin’s bird, the raven was a pagan symbol of war, death and the way to Valhalla." - VikingRune.com