Mount = Furbolg
With what else? Naturally a blue backpack.
How does it work? Naturally the WoW player becomes a Furbolg when summoning said Backpack mount. While in this form the player may walk around as a bear wearing a blue backpack. When the player wishes to move swiftly across the ground he moves forward increasing in speed to which a colorful bird spawns from the backpack and lifts the Furbolg player on it's back running across the land; tracks of course are left behind clearly indicating spoofing nostalgia.
This is also used as a flying mount as when taking flight the Furbolg is seen with a feathered hat and colorful wings.
When not in Ground/Flight Furbolg may use blue backpack as a unit for item storage.