There's gonna be a new RAF mount soon, which will be replacing the zebra.
Not sure, but I think you have to make new RAF (link to your account and buy original WoW)
So if you want zebra, get it now, because in few days we will get this :
Credits : Wow.com and WoW forumsBeginning in just a few days, players who participate in the Recruit-A-Friend program will receive a whole new reward for showing a friend the ropes in Azeroth: the X-53 Touring Rocket, a two-seater flying mount that automatically increases its speed as your mount skill improves (up to 310% speed if you already have a 310% mount). The X-53 will be replacing the current Zhevra mount reward, which is retiring from the Recruit-A-Friend business after a good run. If you've already claimed a Zhevra (or claim one prior to the change), you'll be able to hang on to it, of course. We'll have more details on the new Recruit-A-Friend mount once it becomes available.