The Scandinavian/Norse World Tree, which was believed to support the entire universe. Asgard, the home of the Gods, is shown among the branches. The rainbow Bifrost Bridge connects Asgard to the mortal realm of Midgard, which is encircled by Jormungand, the immense Midgard Serpent. The dragon Nidhogg can be seen gnawing the Tree's roots beneath Helheim, the abode of the inglorious dead. Watercolor.