A single huge eye stares from the forehead of this nine-foot-tall giant. Below this sole orb, an even larger mouth gapes like a cave.
Source: Pathfinder Bestiary
In lost cities inscribed on crumbling walls tell the tales of an ancient civilization of the Cyclops. When dragons and giants ruled the world the Cyclops were at the pinnacle of a lavish culture. Then the rise of men and elves began to populate the world. Quickly the empire fell and their glories were long forgotten. Now Cyclops are nothing more then savage barbarians with an intense hunger and the innate desire to protect their lair.
As the centuries have past the Cyclops have devolved from the height of fine antiquity to a more tribal mentality. Many believe their gluttonous nature may have caused their empire to spiral into decay. The average Cyclops stands 9 feet tall and weighs 900 pounds. Most are completely bald with patches of stringy hair. The most defining feature of the Cyclops is their singular eye.
Combat; Cyclops are large humanoid creatures with the giant subtype. They are a challenge rating 5.
-Ferocity: Cylcops can remain standing even when reduce to zero hits points or more. They are still staggered(can only take a move or standard action each round). They are dead when their hit points are reduced to negative their constitution score. So the average Cyclops has a 15 constitution. They are dead at -15.
-Flash of Insight: Once per day as an immediate action the Cyclops can peer into the future. This allows them to choose the exact result of one die roll before it's made. For example you can choose to have natural 20 on a saving throw roll or maybe choose a 20 on a hit.
-Feats: Cyclops posses a nice array of feats. Of note are cleave, great cleave, power attack, and improved bull rush.
A year ago I had a 6th level Cavalier die because of a Cyclops. The Cyclops choose a 20 on his first roll and then confirmed the roll to score a critical. The average greataxe attack is 3d6+7. Times that by three and you have a dead Cavalier.
Cyclops make great melee combatants. With their superior endurance and the ability to control the dice being their most prominent features.