Wuul Breezerider

Wuul Breezerider is a tauren who comes from Mulgore. His wife died approximately 10 years before the Cataclysm. At an unknown point, he was caught by the Gordunni clan and brought to Dire Maul to fight for their amusement with other slaves. He once tried to escape only to get caught. The ogres beat him and severed his leg. From that moment he was using a wooden peg during fights. He was known as skull-splitter.

When the ogres caught Aramar Thorne, the tauren didn't say his name and said only the contempt name given by ogres - Woolbeard. Stolid, he told the boy that he would kill him, but eventually he was softened by Aram's sketches and bravery during his fights against the gnoll Hackle. Ultimately, encouraged by Aram, he assisted the other slaves in escaping. Although smashed by Wordok, they managed to escape, Woolbeard taking the captive murlocs out of Dire Maul. As Aram's group and Woolbeard's parted ways, the tauren said that it was an honor to meet Aram and revealed him his name. As the tauren and murlocs were leaving, an ogre girl halted them. He was ready to fight her but she only asked them to let her join them. Having seen how King Gordok treated her, they agreed and she immediately supported the one-legged tauren and left the ruined city.

Wuul accepted Makasa Flintwill's plea for help to rescue Aramar Thorne from the Hidden citadel in Hellfire Peninsula on Outland. He came to the Dark Portal valley in the Blasted Lands, reuniting with his friends. Eventually, they fought at the citadel, successfully defeating the Burning Legion demons.

Speculation
As he comes from Mulgore, he is very likely a part of the Thunder Bluff tauren and the Horde.