Greaves of the Shatterer

Source
This item drops from Warchief Kargath Bladefist in the Shattered Halls of Hellfire Citadel.

Graphic matches
Jade-Skull Breastplate and Thatia's Self-Correcting Gauntlets combine graphically with Greaves of the Shatterer in a single suit of armor. They drop from Nethermancer Sepethrea in the Mechanar and Dalliah the Doomsayer in the Arcatraz wings of Tempest Keep respectively.

As armour they are not a bad set of tanking legs, but are little more than a stop-gap to the superior Timewarden's Leggings and Felsteel Leggings.