Assassin Droid
the name given to any number of droid types which were programmed to seek out and eliminate a specific target. They can be programmed to kill an individual, or to take out an entire population. There were also the so-called war droids used as guards and soldiers in many upstart planetary armies. The IG-series of assassin droids was among the best at performing their duties. They were banned during Palpatine's rule as Emperor, after they started to be used against Imperial forces.