There's a dragon in the Blasted Lands named Teremus. He is always seen flying around the map, and can be seen often while running on the path.
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What most people don't know is that he drops [Flawless Dranethyst Sphere]
Before The Burning Crusade, he was a raid boss, and it would take at least 5-10 people to take him down. He usually drops 2-3 orbs, so your chances of getting a sphere were low.
Now, he is much easier.
If you are a beast mastery hunter, you can solo him with relative ease. It might take a few tries, but you can definitely do it.
A Restoration Shaman would be able to solo him simply by keeping earthshield on himself.
Any melee class and a healer would be able to take him out easily.
The orbs can be turned in for 9000XP, which means characters leveling are willing to pay a pretty penny for one of the orbs. They could also be turned in for a garuanteed Bind on Equip Rare item, and a possible Epic one. You could also work out a deal to give them the orb for a price but then they give you the item.
Some notes about him though:
He is immune to all slowing and stun effects.
He is immune to all nature damage and effects.
He has around 80K HP
On cloth, he hits for about 500 and crits for about 1000
He has an AOE fire attack, but at 70 you should have no problem resisting it almost all the time
-Sym