Grey Horse w/ Long Mane

There are 4 tameable creatures with this look.

Grey Horse w/ Long Mane
Can Be Tamed
50Tiragarde Sound
Found in Winterdeep Basin and also south-west of Norwington Estate.
Can Be Tamed
50Rockskip Falls, Tiragarde Sound
Retains its original name after taming.
Freckles canters angrily about a small island in the river west of Norwington Estate.
Can Be Tamed
50Boralus & Hatherford, Tiragarde Sound
Horde hunters can tame this horse the usual way, but it is friendly to Alliance and can only be tamed by Alliance hunters using the toy "N'lyeth, Sliver of N'Zoth" while in War Mode. It can be found in the stable just south-east of Proudmoore Keep, and around Hatherord to the north of Boralus.
Can Be Tamed
50Tidebreak Summit, Stormsong Valley
Also found just north of the Deadwash.
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.

Matching Mounts