Its the Wrathfull Gladiator tabard. I also got the Relentless one, yet I cant find a mog with it yet, except for the MOP CM set <3 Sadly I dindt do MOP CM on my paladin but on my warlock...
Wrathfull :
http://www.wowhead.com/item=51534/wr...diators-tabard
Relentless:
http://www.wowhead.com/item=49086/re...diators-tabard