Droid Zero was a V6-series pilot droid.
Droid Zero developed a superiority complex, which overode some of the behavioural inhibitors built into its core programming and eventually led to the droid believing that it was demeaning for droids to serve sentient beings. After being assigned to a senatorial transport ship, Droid Zero infected the ship's entire complement of astromech droids with its programming, then transferred to a new ship and repeated the process a number of times. As a result, there became dozens of infected droids across the galaxy, which started directing their owners' starships into hazardous areas. Government droid technicians began scouring the galaxy to try and find Droid Zero, but the droid continued to spread its programming.