Fierce creatures with an unrelenting hunger, Flesh Raiders were believed to be Tython

Tython Planet

's only sentient natives. No one knew where the Flesh Raiders came from. Some speculated they were once a civilized people, driven to cannibalism and madness over years of isolation. Others feared they were the result of dark side experiments.
They were at least partially intelligent, capable of building shelters and assembling basic weapons from scavenged technology, but attempts to communicate had all ended violently. Known for devouring their prisoners and any animals they come across, the Flesh Raiders were formerly content to live in their primitive, bone-strewn camps in the hills.
Shortly before the end of the Cold War

The Cold War Event Cold War (3653BBY - 3642BBY)

, the expansion of the Jedi Order

Jedi Order Organization Galaxy-Wide Organizations

and the Twi'lek Pilgrims seemed to have drawn the Flesh Raiders into the valleys, and they began to attack

Flesh Raider Uprising Event Cold War (3653BBY - 3642BBY)

both neighbors in an organized manner

Flesh Raider Forces Organization Planetary and Sector

, using modern weapons instead of clubs and axes.