You must learn a special skill to tame Cloud Serpents, which is different to the skill required to tame other Lesser Dragonkin. Pandaren hunters gain the skill automatically, but hunters of other races must learn it from the tome How to School Your Serpent, which may purchased from San Redscale at The Arboretum in The Jade Forest. You require Exalted standing with The Order of the Cloud Serpent to read this tome, but the learned skill is account-wide. You can even purchase and read this tome on a non-hunter character.
Flies around the northern portion of the Isle. The Wandering Isle is open to any character on your account after you complete the Pandaren Heritage quest chain. You reach it via the same balloon you used at the start of the chain.
Level scaling: Most NPCs will scale with the Hunter's level, within the constraints of their level range. Hunters can tame regular NPCs up to 2 levels higher than them, but can only tame elite NPCs of the hunter's level or below.