Echoes of Rezan
Drops from Burgy Blackheart. As of today 21/9/2018 the World Quest has appeared for EU servers at least. The quest shows that it awards only War Resources.
The 
Echoes of Rezan is a toy obtained by completing the World Quest Wrath of Rezan, which awards the toy automatically upon logging out and back in after completion.
Guide awaiting review
Wait for Wrath of Rezan
The World Quest Wrath of Rezan is not always active — it can take many weeks to appear in your quest tracker. The quest is available to both Alliance and Horde players.
Complete the World Quest
Complete Wrath of Rezan when it appears. The quest reward listed may show only War Resources, but the toy is granted automatically upon completion.
Relog to receive toy
After completing Wrath of Rezan, log out and log back in — the toy will then appear in your Toy Box.
Enable BfA toys in filter
If the toy is not visible in your Toy Box, click Filter at the top of the Toy Box, disable Usable Only, then under Expansion check Battle for Azeroth to make it appear.
Tips
Using Echoes of Rezan plays a T-Rex-style dinosaur roar and causes your character to lean back dramatically.
