Brain worm

"Watch as my child enters your Jedi friend."

- Karina the Great taunts her captives

Brain worms were a species of parasitic worm from the planet Geonosis which were capable of entering the body of a host and taking control of it. During the Clone Wars between the Galactic Republic and the Confederacy of Independent Systems, the Geonosian Queen Karina the Great used brain worms to control a host of undead Geonosians. After Republic forces defeated Karina and her minions, a brain worm managed to infect the clone trooper Scythe and used him to infect a number of other clones and the Jedi padawan Barris Offee onboard the Republic medical frigate TB-73. Jedi padawan Ahsoka Tano was able to prevent the infection from spreading further by using extremely low temperatures to combat the worms, saving Offee and most of the troopers.