As we were working on Herezh, our survival multiplayer game, Hamza Belhoussine and I worked on Yggdrasil.
It's a world-tree, used as a boss level in forest biomes. The main goal when designing it was that he could be then the forest from everywhere, in the center of a forest, being an imposant godlike tree who could serve as a landmark.
Herezh Kickstarter right here : https://www.kickstarter.com/projects/herezh/herezh-generations-of-heroes
https://www.artstation.com/hamzadrissi