Bioweapon A bioweapon was a genetically engineered developed and used as a military weapon . It was often , although not always , designed to affect only a specific species or number of species . History . Bioweapons have been in use in various times and by various cultures in the course of history . Apparently , their use was not exclusive to the known galaxy either , as Ship remembered the use of the Plague bomb in an ancient war in a far - away galaxy . In addition , the extradimensional Charon were known to employ bioweapons extensively . Bioweapons such as Trihexalon were known in the time of the Old Republic . During the Clone Wars , the Separatists employed bioweapons such as the Loedorvian Brain Plague and Blue Shadow Virus in their struggle against the Republic . Rokur Gepta used a bioweapon contained in his electromagnetic torpedo to devastate the planet Tund , and kill its inhabitants around 5 BBY . The Galactic Empire developed a number of bioweapons during its time as the dominant galactic government , perhaps the most infamous being the Emperor ' s Plague and a number of other species - specific agents . After the Empire ' s fragmentation , the various succeeding Imperial Warlords continued to develop new pathogens . The most infamous use of bioweapons in Galactic history was probably the deliberate release of the Krytos virus on Coruscant by Ysanne Isard . As technology progressed , bioweapons became more refined . In 11 ABY , Imperial scientists had developed sophisticated Nano - destroyer s , artificial viruses keyed to a target ' s genetic makeup that were not only incurable but also completely undetectable by conventional medical means . During the Yuuzhan Vong War , both sides deployed bioweapons . The extragalactic Yuuzhan Vong destroyed several entire planets , most notably Ithor , using various biological agents , and infected a number of Jedi with Spore disease s . Although the New Republic never sanctioned its use , Galactic Alliance Intelligence deployed the Alpha Red weapon on the planet Caluula , wiping out its Yuuzhan Vong population but destroying the natural environment . Prior to 127 ABY , agents of the One Sith including Sith Lady Darth Maladi and Yuuzhan Vong Shaper Zenoc Quah sabotaged the joint Jedi - Yuuzhan Vong Ossus Project which aimed to terraform war - torn worlds . They infected the terraforming processes with the Vongspawn virus that caused flora and fauna to mutate and painful growths to appear on sentients . The ensuing tensions sparked the Sith – Imperial War which consolidated Sith - Imperial dominance over the galaxy by 130 ABY . During the Second Imperial Civil War , the Sith scientist Vul Isen developed viral spore s capable of poisoning all organisms on a planet ' s oceans within days , rendering it uninhabitable . These were deployed as part of the Mon Calamari Genocide on Dac and later on Da Soocha . By 138 ABY , Darth Maladi had developed an improved version of Alpha Red known as Omega Red which was capable of eradicating entire species . Following the deployment of Darth Krayt elite Sith troopers during the Battle of Taivas , Emperor Roan Fel made a deal with Maladi to deploy the weapon during an assault on Coruscant . In reality , this played into the hands of her master Darth Krayt . It was capable of destroying all sentient lifeforms with the exception of members of the One Sith who were immune to its effects . However , Fel was killed by Antares Draco before he could deploy the deadly bioweapon on Coruscant . Workings and use . Bioweapons could be synthetically developed , such as Nano - destroyers , or refined from existing substances , such as the Alpha Red pathogen , which was refined from Bafforr tree pollen . While most bioweapons did not see general use ( those employed by the Yuuzhan Vong being the exception ) , they could be used for a variety of purposes . Lethal pathogens such as the Hive virus could be used for annihilating entire populations , while others were more subtle . For example , the Vira606 was administered by the Imperial Security Bureau to some of its agents , making them dependent on constant antiserum injections and ensuring their loyalty .