Yennu's Kite
Drops from Yennu's Kite. Treasure is located in zone in Crumbling Cliffs Glide up to the tree where you see couple of Kite Adventurers & Then follow the branch to the left Treasure is on top of a tree branch.
The 
Yennu's Kite is a toy that drops from a treasure chest located in the Crumbling Cliffs area of The Waking Shores and is required for the Treasures of The Waking Shores achievement.
Guide awaiting review
Travel to Crumbling Cliffs
Fly west from the Uktulut Backwater camp to the Crumbling Cliffs in The Waking Shores. Between the mountains you will find a large rock with a large tree on top of it at 46.71, 31.21.
Speak with Yennu
Before climbing the tree, you can speak with Yennu, who stands in front of the tree at 46.76, 31.13. You do not need to return the kite to him, as he has plenty in his collection.
Climb or Glide to Treasure
Use your dragon to glide up to the tree where Cynthia Cloudwhisper and Travis Moreau are standing at 46.74, 31.26. Alternatively, walk up the stairs and use the wooden steps nailed into the tree to climb up without needing to land your dragon. Once on the tree, follow the large branch to the left and carefully walk to the end to collect the treasure chest containing Yennu's Kite. While you are there, Cynthia Cloudwhisper also sells the 
Windscale Rider.
Tips
If you struggle to land your dragon on the tree platform, look for the wooden steps nailed into the tree trunk — these let you walk up from ground level without any flying precision required.
