In the history of the galaxy, it is quite extraordinary for a droid to change the level of its self-awareness, particularly to the degree of personal transformation that 4-LOM achieved prior to its becoming one of the galaxy's fiercest bounty hunters.
4-LOM was a late model protocol droid serving as a valet and human-cyborg realtions specialist on the passenger liner Kuari Princess. With a TranLang III Communication module giving it knowledge of more than seven million languages, 4-LOM acted as an interpreter between the rich guests and the ship's computer. The droid was entirely aware of what the guests - and their possessions - were doing at all times. As entertainment, the protocol droid began engaging in a series of games, simulating how best to steal valuables. The games became serious, though, when the droid and the computer began to alter each others' programming. Soon, unexplained and perfectly executed thefts had the Kuari Princess owners worried. No one suspected 4-LOM, the benevolent and passive droid. Eventually, 4-LOM's altered programming allowed it more sentience, and it became bored with the ease with which it robbed from the space liner's guests. Off ship, the protocol droid became a master thief and information broker for many of the galaxy's most powerful crime lords, including Jabba the Hutt.
Jabba realized that 4-LOM would make an excellent bounty hunter, but the droid reminded him that its programming would not allow him violent actions. Jabba offered the droid a deal: he would refit, reprogram, and rebuild 4-LOM in exchange for its services. The droid agreed, and Jabba soon had the smartest bounty hunter in the galaxy working for him. The crime lord paired 4-LOM with a Gand hunter named Zuckuss, whose intuition and ability to outguess his opponents worked perfectly in combination with 4-LOM's analytical skills. For a time, they were two of Jabba's favorite hunters.
A year after the destruction of the Empire's first Death Star, Darth Vader sent out a call for bounty hunters to find Han Solo, whose capture he believed would lure Luke Skywalker to him. Jabba sent 4-LOM and Zuckuss as "nonofficial emissaries." They arrived on Vader's Super Star Destroyer Executor, finding that four other bounty hunters had also been chosen for the hunt: Boba Fett, Dengar, IG-88, and Bossk. Unfortunately for the paired hunters, Boba Fett was the one who tracked the Falcon to the Bespin system. Fett recieved not only the bounty from Vader, but also the carbonite-frozen body of Han Solo to deliver to Jabba the Hutt. Pleased to have Solo hanging on his wall, Jabba did not have his own hunter pair killed for their failure. The droid and the Gand were much too useful. 4-LOM and Zuckuss would have many more successful missions in the future.