If you happen to be horde, I would strongly recomend you get the faded wizard hat from aszhara.
It have a 30 min duration, and cooldown. Dont need to have it equipped for keeping the effect either.
And it can make you into, bloodelf, undead, goblin, orc, human, night elf, troll. Both female and male for some of them as I've seen.
Basicly any of xylems aprentice's you can turn into as far as I know.
If you are alliance, well. That sux, and RNG is a bitch!