Yuuzhan Vong

A people who came from beyond the known galaxy. Their culture was built on grown living organisms: ships, weapons, armor, and tools were living creatures bred for the necessary tasks, and machinery as such was considered an abomination.

The Yuuzhan Vong were divided into castes, namely warriors, priests, shapers, craftsmen, and servants, and worshipped their own gods, who demanded sacrifices and bodily mutilation as a sign of piety. Their distinctive feature was their invisibility in the Force, because of which the Jedi could not sense the enemy by ordinary means.

Their invasion unleashed a war that engulfed the galaxy: worlds were devastated, populations were turned into sacrifices, and Coruscant was captured and transformed. The war undermined the New Republic, which was succeeded by the Galactic Alliance, and ended in the defeat of the invaders.