These are all Mounts. Mounts are basically beasts that you can obtain if you play through a Dungeon, Raid, or even buy some of them if you have your Reputation at Exalted with a Certain City. For Ex. The Dragon on the top row in the middle "The Red Drake" can be obtained if your reputation with this city "Wyrmrest Accord" is at Exalted. If you want some of the New one's. For Ex. The Cloud Serpents at the bottom of the list, you will need to be dedicated to playing everyday in the Continent Pandaria at The Order of the Cloud Serpent. You will need to complete your chain of "DAILY" Quests that earn you Reputation and if done correctly you will finish in about roughly 2 1/2 weeks or more to get your reputation to Exalted. It takes time to complete these Achievements but once you have it you feel so Rewarded.