Ironjaws
The Ironjawz are one of the orcs (or orruks, depending on how anal you are on copyright) to be found in the Age of Sigmar. They are THE 'ardest mothafuckas in the setting and the most killy fuckers orckind has ever offered in ANY setting.
The Origins
There was this era between the epic buttfucking of the Old World and the Age of Sigmar where the big totes-not-Conan gathered the incarnates and waged war on the Gods of Chaos' electric boogaloo. Of the gods, Gorkamorka (not to be confused with that other game) was the champion of Sigmar, and tales tell how they battled constantly and did things that would make the old norse/greek gods blush on how epic they were. BUT, Gorkamorka grew tired, split and said that Sigmar ought to make auditions for a new champion, since he'd go out of town. In the meantime he punched something uber-hard once and splinted his fist, and from said splint was born Gordrakk, fist of Gork (pun apparently was intended), first of the greenskins of the Age of Sigmar. From here onwards they'd grow non-stop.
Ghur, the realm of beasts, was once fairly lush but the green tide gordrakk led razed it to the ground. Archaon, seeing the threat they supposed, tried to annihilate them but the Grand Marshal utterly forgot that the greenskins thrive during conflict to his hitleresque attempts bore him no fruit (on the contrary!).