Yggdrasil

The World Tree—“Odin’s horse.” Named after a gallows, Yggdrasil holds all nine worlds in its branches and roots. It is the spine of the Norse cosmos.

Unlike eternal, indestructible pillars in other mythologies, Yggdrasil is alive and dying. Its bark rots on the sides. A dragon gnaws at it from below. Four deer strip its leaves. A squirrel carries insults up and down its trunk. The only thing keeping it alive is the daily work of the three Norns, who pour water and pack healing clay into its wounds.

The cosmos does not sustain itself. It requires constant maintenance. If the Norns stop their work, the nine worlds collapse.