Yggdrasill is a central figure in Norse mythology, often depicted as a massive, sacred tree that connects the nine worlds. This immense ash tree is considered the axis mundi, or the world tree, symbolizing the interconnectedness of all realms, including Asgard, Midgard, and Hel. The tree is home to various creatures, including a dragon named Nidhogg that gnaws at its roots, and a squirrel that scurries up and down its trunk. Yggdrasill is also associated with the cycle of life, death, and rebirth, reflecting the Norse belief in the eternal nature of existence.