Broxar was born and raised in the Warsong Clan. Ever since he was small, he always had a knack for fighting. Serving in many battles soon gave him the title of Broxar "Ironskull" for even using his own head in battle—not intelligently, though. Broxar's cranium is strong: he stops arrows aimed straight for his head; also, when he head-butts his enemies, they have the unfortunate experience of their skulls caving in on them. When Broxar reached Outland, he found a demon egg that he was going to sell to a goblin for extra gold, but before he could sell it, the egg hatched and the small demon gurgled. For some reason, Broxar was won over by the small demon and has kept it as a pet since; its name is Wiggles.
In Broxar's midlife, he served as a mercenary for goblins in Gadgetzan until a gnome framed him for robbing the bank of Gadgetzan, which was an idiotic accusation in the first place. But the gnome somehow had enough evidence to get him banned from Gadgetzan, thus inducing Brox's never-ending hatred for gnomes.
The present time is how Brox got his name of "Ironskull." Dwarven cannon fodder cannot even pierce Broxar's skull; the tips of arrows snap off from impact. The attacks he has made with his head over the years are what caused Broxar's intelligence to dwindle to the point where he is on the verge of going on primal instincts.