- "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 and had the potential to control entire societies. 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 in Tango Company as well as the Jedi Padawan Barriss 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.
- Star Wars: The Clone Wars – "Legacy of Terror" (First appearance)
- Star Wars: The Clone Wars – "Brain Invaders"
- (First identified as Brain worms)
- Star Wars: Absolutely Everything You Need to Know
- Star Wars: Galactic Atlas
- Star Wars: The Visual Encyclopedia
- Star Wars: Absolutely Everything You Need to Know, Updated and Expanded
- Star Wars Helmet Collection 31 (Databank A-Z: Kaminoans–King Katuunko)
- Star Wars Helmet Collection 41 (Databank A-Z: 'Occupier' Tank–Oola)
- Star Wars Encyclopedia of Starfighters and Other Vehicles
- Star Wars Helmet Collection 60 (Highlights of the Saga: The Second Battle of Geonosis)
- Rise of the Separatists
- Star Wars: How Not to Get Eaten by Ewoks and Other Galactic Survival Skills
- Star Wars: The Clone Wars: Character Encyclopedia - Join the Battle!
- "Anakin Skywalker" – Star Wars Encyclopedia