Hey, thought I'd post this I found when questing in Un'Goro on my mage.
Right when you exit Marshall's Refuge, there's a lot of tar mobs, at Lakkari Tar Pits, in the north part of Un'Goro.
Here you'll find these four mobs:
Tar Beast - NPCs - World of Warcraft
Tar Creeper - NPCs - World of Warcraft
Tar Lurker - NPCs - World of Warcraft
Tar Lord - NPCs - World of Warcraft
Level 50-54 tar monsters, so you can start here already at lvl 48. Lower level ones are more close to the volcano.
Now, the thing about these is that they have FIRE VULNERABILITY, meaning they take a lot more damage from fire spells / effects. I was one and two shotting them on my mage, for very fast leveling. They took sometimes up towards 800 bonus damage from one spell. Very nice mobs to grind for a fire mage / fire lock.
Hope it helps someone to get out of those boring last levels and into outland