The Dark Bargain
When the Gods first turn their eyes to Kallan, they created the Giants, hoping to create beings whose immense strength and power would be a monument to their own power. However, they created beings who became jealous of the power the Gods wielded, and decided to take the power of immortality for themselves. They engaged the Gods in a millennial war, during which the mortal races were created. In the end, the Gods won, and trapped the giants beneath the surface. However, the Gods grew lax and the Giants broke free. They rampaged across half the continent. The Gods raised a range of mountains laced with iron, which stopped their advance. However, they were satisfied with their new domain, enslaving and even destroying the inhabitants.
Over the next several centuries, they grew displeased with their new prison, and decided to move past the Iron Peaks. However, the Gods had seen this coming, and they had already chosen the Dwarves to be the defenders of the Mortal Realm. After three centuries of failure to breach the defenses, the Giants chose to sit back and wait, looking for a crack in the defenses. In the many centuries since, the Dwarves have remained steadfast in their duties, even creating automatons to train new generations of warriors. The other races, however, have forgotten all but the legends of the wars and skirmishes.
The only exception to this is the Titans. They gave up much of their power to not be on the bad side of the Deities, and they now live with the Dwarves.
Large: -1 AC & Attack Rolls, -4 Stealth, +1 to CMB & CMD, Reach 10 ft
Speed 30 ft
Ability Score Adjustments: +2 Str, +2 Con