Animals In Norse Mythology

At the very top of Yggdrasil there lived an giant eagle named Hraesvelg. And down by the roots of the tree lived a dragon named Nidhug. The eagle and the dragon were bitter enemies. A squirrel named Ratatosk, was spending a lot of time each day, running up and down the tree. Ratatosk did whatever he could, to keep the hatred between the eagle and the dragon alive.