HK-47

HK-47 is a Hunter-Killer Assassin droid built by Darth Revan and used by him to assassinate any individuals the Sith Lord deemed too great a threat.

History
Shortly before Revan's capture by the Jedi order, and his amnesia, HK-47 was critically damaged while in Mandalorian space and, as was protocol for Sith droids, his memory was erased. Over time, HK-47 was bought and sold between several different owners across the galaxy, many of whom he murdered himself. Eventually, the droid was repurchased by Revan on Tatooine, although he himself had lost all memory of his identity as a Sith Lord and had returned to the light side of the force as a Jedi. Aiding Revan in his quest to find the star maps in order to locate the Star Forge, HK-47 eventually regained his memory as Revan learned who he once was and confessed his identity to his companions. Despite Revan now being a Jedi, HK-47 remained loyal to him and proved instrumental in fighting the Sith Empire and destroying the Star Forge.

Personality
Largely due to having a greater degree of autonomy and adaptive programming than other HK droids, HK-47 would eventually go on to become one of the longest-living and most succeful assassin droids in the galaxy. He displays an obvious dislike for organic lifeforms, whom he refers to as "meatbags", and displayed clear sadistic and even sociopathic tendencies; often expressing an enjoyment for killing and eagerly requesting his master's permission to kill someone he considers annoying. He is also shown to be somewhat egotistical, consifering himself superior to other droids. HK-47 has also demonstrated admiration for Revan for the atrocities he committed as a Sith Lord, although he remained loyal to him after he turned away from the dark side of the force.

Eventually, HK-47 was temporarily modified with a protocol pacifist package, reprogramming him with an appreciation for peace and sympathy for his targets, to the point he became appalled at the mere suggestion of harming a living thing. After removing this package and having his original programming restored, HK-47 requested any further packages installed into him be scanned beforehand, horrified by the idea of becoming a pacifist.