Candorite

Candorites were small black hairless rodents that developed on Corellia. Though initially regarded as pests, Corellian merchants began transporting these rodents to numerous other worlds as livestock for food. In the process, these merchants had been unknowingly spreading the Candorian plague which laid dormant in most of these creatures. As a result, several dozen worlds encountered this plague which killed millions during the Republic Dark Age.

Most Human populations eventually developed a resistance to the plague until the time of the Galactic Empire, during which Imperial scientists genetically engineered a strain of the Candorian plague using genetic material extracted from candorites. The Empire used the modified plague as a biological weapon during their siege of Dentaal. The Imperials also attempted to release the plague on Mandalore, which had suffered the plague millennia prior, though a group of Supercommandos including Naastau managed to destroy the research facility where the plague missiles were stored.