- "I assure you, sir, that this bomb only works on droids."
- ―Sionver Boll
The electro-proton bomb was designed by Sionver Boll for use by the Galactic Republic, but the bomb's use had unintended consequences. While it was successful at taking out droids in service of the Separatist Alliance on Malastare, it also upset the planet's eco-system, awakening an ancient and powerful creature known as the Zillo Beast. A weapon derived of the bomb, designated as the Electro-Proton Bomb/Defoliator, was rumored to be developed by the Galactic Empire. It combined the electronic elements of the electro-proton bomb and elements of the defoliator, a Separatist creation, to create a bomb that could devastate robotics and organics.
- Star Wars: The Clone Wars – "The Zillo Beast" (First appearance)
- Star Wars: The Clone Wars – "The Zillo Beast Strikes Back" (Appears in flashback(s))
- Star Wars: Galactic Atlas
- Star Wars: The Rebel Files
- Star Wars Encyclopedia of Starfighters and Other Vehicles
- Star Wars: Alien Archive
- Star Wars Helmet Collection 79 (Databank A-Z: Zabrak–Zillo Beast)