Rakghoul plague

The rakghoul plague, alternatively referred to as the rakghoul disease or rakghoul virus, was a disease engineered by the ancient Sith Lord Karness Muur. Muur, seeking a means to escape death and achieve galactic conquest, forged a Sith amulet that came to be known as the Muur Talisman, an item into which Muur poured his mind, will, and Sith magic. The Muur Talisman's power could almost instantaneously turn any nearby sentient being into a mindless rakghoul, a Sith-spawned mutant subservient to Muur's will. But the talisman's power was not perfect, and it could not transform Force-sensitives or beings belonging to certain non-Human species into rakghouls, and thus Muur designed the rakghoul plague to compensate for this weakness. The virus-like plague, carried by every rakghoul in existence at the time, could be spread to another being by a bite or a scratch from a rakghoul's claw. The victim would then suffer through an incubation period lasting approximately six to forty-eight hours before being transformed into a rakghoul, one fully capable of spreading the Sith-made disease on to further victims.

In the years before, during, and after the Mandalorian Wars, the Rakghoul Plague spread nearly unchecked through the Undercity of the planet Taris, and well over a million Mandalorian Neo-Crusaders fell victim to the plague's effects on the ice-covered world of Jebble. Though the rakghouls were widely thought to have become extinct at a time prior to the rise of the Galactic Empire in 19 BBY, the Rakghoul Plague—and by extension, the rakghouls themselves—would continue to exist in the galaxy by the powers of the Muur Talisman until 137 ABY, when the dangerous Sith artifact was finally destroyed by the Jedi Cade Skywalker on the Deep Core Imperial world of Had Abbadon.

Text and facts from the “Rakghoul plague/Legends” article on Wookieepedia, licensed under CC BY-SA 3.0. Modified for this site.