Four stags or harts (male Red Deer) eat among the branches of the World Tree Yggdrasill. According to thePoetic Edda, the stags crane their necks upward to chomp at the branches. Their names are given as Dáinn, Dvalinn, Duneyrrand Duraþrór. An amount of speculation exists regarding the deer and their potential symbolic value.
Ratatoskr (Old Norse, generally considered to mean “drill-tooth” or “bore-tooth”) is a squirrel who runs up and down the world tree Yggdrasil to carry messages between the unnamed eagle, perched atop Yggdrasil, and the wyrm Níðhöggr, who dwells beneath one of the three roots of the tree. Ratatoskr is attested in the Poetic Edda, compiled in the 13th century from earlier traditional sources, and the Prose Edda, written in the 13th century by Snorri Sturluson. Scholars have proposed theories about the implications of the squirrel.