The original Rakghoul, also known as Patient Zero, was the first Rakghoul ever created, a product of Karness Muur's dark experiments. Darth Acina kept him in suspended animation within the Arcanum until Tagriss, a renegade Sith Lord loyal to the Dread Masters, released him.
During the Golden Age of the Sith, a humanoid male whose name has been lost to time, known only as "Patient Zero," lived. Karness Muur, one of the earliest Dark Lords of the Sith, employed Sith alchemy to develop the Rakghoul plague, a virulent disease intended to transform victims into an army of mindless creatures to dominate the galaxy. This individual became the initial subject infected by Muur's creation, transformed through the Sith magic emanating from the Muur Talisman.
Millennia afterwards, Darth Acina, a recent inductee into the Dark Council, confined him to stasis within the Arcanum, a space station designed to safeguard perilous Sith artifacts. Nevertheless, Lord Tagriss attacked the station under the command of the Dread Masters, liberating Patient Zero from his imprisonment.