Gruul's Lair

The Cudgel of Kar'desh quest is associated with killing Gruul.
Tier 4 Legs token is dropped from Gruul.

Following up on the quote from Tigole i assume completion of this quest or possession of this item will activate this achievement.

Quote: http://forums.worldofwarcraft.com/thread.html?topicId=8557074411&sid=2000

If you have http://www.wowhead.com/?achievement=432 Then you automatically have this achievement done, even if you don't have any of the items in your inventory :P

Did it today 9/11 with Shadow Priest and Rogue.
1)
Nuked Kiggler the crazed first (cuz of his perma sheep).
After that we took Olm the Summoner to get rid of the fear.
After that Blindeye the seer and Krosh Firehand.
And last High King Maulgar.

2)
Gruul the dragonkiller was just tank and spank!

HF!