This is from the Diablo
Baal is a demon from the Diablo setting. He appeared in the promotional trailer for the Heroes Founder's Pack.
Baal, Lord of Destruction, is one of the Prime Evils and Great Evils of the Burning Hells.
As with all of the Great Evils, Baal was spawned from one of the seven heads of the Great Dragon Tathamet. He lorded over the Realm of Destruction in Hell.