The Great are a race of gigantic, monstrous people. While generally human in form, they're incredibly powerful, each individual capable of destroying multiple cities, unarmed, in a single attack. They're extremely advanced technologically.
In the distant past, they attacked the planet Shri for unknown reasons, forcing the disparate city-states to cooperate for the first time in history to defend themselves. This led to the creation of the Zigori. After a civil war between the Zigori and the normal-size humans had begun, the Great ceased their attacks for unknown reasons. (Squids in Forests: "Fried Calamari")
A number of Figs were left on Shri following the Great's attacks, where they were generally considered vermin. (Pierre Series: "Descent")
A Great was seen in a coma, The Crodin were extracting its DNA in order to replicate them for war. (Escape The Crodin: Epic Worlds PCG)