Black from head to toe, with bluish sheen and an unmistakable hoarse voice: this is the common raven. Though it may not look it, it is the largest songbird in the world, a relative of sparrows and blackbirds. But what really makes it special is its mind. Ravens solve complex problems, plan for the future and even keep tools to use later. They imitate the sounds of other animals and even human words. And they love to play: ravens have been seen sliding down snowy slopes just for fun. It is no wonder it appears in so many legends. In Norse mythology, the god Odin had two ravens, Thought and Memory, who flew around the world and told him everything they saw. Intelligent, curious and playful: a true genius with feathers.