an illustration from a 17th century Icelandic manuscript of the Yggdrasill Tree and the creatures that inhabit it.

In Norse mythology,the Yggdrasill Tree or World Tree is a Gigantic Ash Tree that holds the nine realms of the world together. Its huge branches stretch to the ends of the Earth and to heaven. Its roots dig deep into the Norse's interpretation of Hell. At the top of the tree, there is an unnamed eagle with the hawk, Veðrfölnir, perched on his head, that exchanges harsh words with the Níðhöggr that gnaws at the tree's roots. Ratatöskr,a squirrel takes the messages between the two. It is said that the Níðhöggr will topple the tree and destroy the nine realms of the world at Ragnarok, the Norse Judgement day.