User blog comment:The Wayward Daughter/Coming Soon..../@comment-40228173-20190922102120/@comment-25781987-20190922105337

The Yggdrasil leaf is a reference to an old running joke. Back when we had the wiki chat, I would use the Yggdrasil leaves to try and revive chat (after 2 minutes of silence). Other users would also try to revive the chat using the leaves.

It was a nod to the leaves from the Dragon Quest series (IX was and still is my favourite game of all time) rather than the tree in Nordic mythology.