Red Flying Cloud

Exalted with Lorewalkers just got cooler.

if you mount up with your weapons unsheathed, it wont automatically sheathe them like with other mounts. looks pretty bad ass.

To get this mount you have to be exalted with "The Lorewalkers". A vendor named Tan Shin Tiao sells it. As Yuyuli mentioned in a different comment you will get exalted through 9 achievments:

The only way currently to get Lorewalkers reputation is through 9 Achievements listed below:
Ballad of Liu Lang
Between a Saurok and a Hard Place
Fish Tales
Heart of the Mantid Swarm
Hozen in the Mist
The Dark Heart of the Mogu
The Seven Burdens of Shaohao
The Song of the Yaungol
What Is Worth Fighting For

Upon completion of one Achievement you get a Mail with a Quest Item that also rewards reputation with Lorewalkers.
The Ballad of Liu Lang each Achievement will give you one of these, same name as the Achievement.

8 Achievements will get you to Exalted.

This page shows you where they all are. Exploration in MOP