They are Dragonmaw -- a clan that seems a little out of place in the name department, having existed long before dragons ever arrived on Draenor. However out of place that name may have been at the time, the clan lived up to it with brutal efficiency upon traveling through the Dark Portal and arriving on Azeroth. Yet for all its bravado, all its strength, and all its extremely powerful artifacts of questionable origin on its side, the Dragonmaw didn't really flourish. In fact, it found itself ironically subject to the manipulations of those it tried to subjugate, over and over again.
One orc woman saw the path her clan was destined to travel, the seed of corruption that was quickly threatening to tear the Dragonmaw apart, and feared for the fate of her clan. But when given a chance to make a difference, she seized the opportunity, killed her own Warchief and was rewarded with the chance to lead the Dragonmaw at the side of the Horde. Zaela may not have a lot of story behind her just yet, but make no mistake -- she will do whatever it takes to guarantee the safety and survival of her clan.
It's a pity that her methods involve allying with the most hated orc on Azeroth.