Joopa worms, also referred to as joopas, were a type of gigantic, worm-shaped, non-thinking species that dwelled beneath the surface of the arid planet Seelos. These creatures could reach lengths of up to 21 meters. A ring of vibrant red eyes, lengthy pink tongues, and tough, plated shells protecting their soft bodies were among their defining characteristics. A membrane located behind their eyes caused light to reflect off the retinas, giving their eyes a glowing appearance. Since they had no teeth, they consumed their prey in one gulp. They particularly enjoyed the taste of Lasat. While remaining hidden underground, they were known to utilize their grasping tongues to seize prey from the surface, though they could also surface to launch direct assaults.
After the proclamation that established the Galactic Empire, a few clone troopers from the disbanded Galactic Republic (Rex, Wolffe, and Gregor) chose to retire on Seelos, where they hunted joopas, which Gregor considered a culinary delight. Sometime following the fifteenth anniversary of Empire Day, the Spectres, a rebel group, journeyed to Seelos in search of the clones, hoping that their expertise could aid the growing rebellion. Garazeb Orrelios, a Lasat member of the Spectres, volunteered to serve as bait to assist the clones in capturing a joopa.