Great… Undead Pigeons…
Jokes aside i believe it’s possible the player got it during the first hours of the release. It’s a reward from the Gnome’s Vault if i’m not mistaken, and the gnomes at the time would spawn regularly and you could get the Vault Key from them if lucky.
Edit as it turns out i was indeed mistaken:
Sorry about that @Svetlana.
Are Valravens dropping on chests or something? 