They are giant humanoid creatures that wear light armor and wield giant clubs. Unlike Titans, Gigas are very slow and lethargic monsters that attack by sliding their weapons across the ground which is followed by a vertical slam. They can also perform a charge attack that leaves them vulnerable following its completion.
When their armor is broken, a Gigas will enter berserker mode, causing their skin to become black. They will take increased damage but also possess higher attack power.
The Undead Gigas, which were created through Three's experiments, possess greater power and have the ability to use a destructive foot stomp attack that deals heavy damage.