Who hasn't ever wanted to ride a flame breathing dragon?
The mount would be summoned by a Dragon Egg:
The egg could be a drop found as a treasure from the Lihzahrd Dungeon, Or maybe as a drop from the boss suggestion of this thread. And upon use, it would give the Dragon Mount buff to the player:
The Dragon itself would be a very versatile mount, being able to fly, walk and maybe burn all of your enemies