He is the Arrancar No.15, Yylfordt Granz (or Ilforte Granz), and is one of Grimmjaw's five fraccion.
We see him a couple of times throughout the anime/manga, the first of when Grimmjaw decides to invade the real world and takes his fraccion with him. Ilforte fights Renji, and turns into a bull with his release.
Other times he is mentioned as being the older brother of Espada No. 8 (Szayel Apporo Granz), and we also see him again during the story of how they started out in Hueco Mundo as Adjuchas.
i havent seen him before..... i mean there is the fight with everyone there but i havent seen him....
There is the old dude
the drunk sorta guy like one of the captains, that doesnt want to fight
also that crazy big titted chick.
And the rest are all dead from the raid on hollow land...
Maybe he is a add?
I dont know.