Battle of the Doomed Gods (by Friedrich Wilhelm Heine, 1882)
The raven is a bird of Odin. He had two, Huginn and Muninn, whose names meant Thought and Memory. Each morning, he sent both birds out into the world and each evening they returned to tell him all that they had seen and heard.
“I always fear that Thought may fail to wing his way home, but my fear for Memory is greater.”