Can be tamed.
Located in Old Drust Road, Tiragarde Sound. Horde hunters can tame this Workhorse 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. Found just across the bridge, to the east of Vigil Hill island. Only one is present at a time, but if the current one isn't the colour you're after you can kill it and it respawns quickly.