Yggdrasil refers to the tree in Nordic mythology. In Nordic mythology, the branches of this huge tree constitute the whole world. The tree species of this tree is ash tree, which is as high as the sky. There are nine kingdoms derived from this tree.

The so-called "Yuk" means frightening. It is also another name of the lord god Odin. And "trahill" refers to the horse, so combined it is "Odin's horse". Its origin is that Odin once hung himself on a tree and stabbed himself with a long gun kungunil, so he found the Luen script.

Source: @ivanmogarra