4-LOM, pronounced "FOR-ELLOEM," started as a LOM-series protocol droid with high aspirations. However, he defied his original programming, reinventing himself as a galactic thief and subsequently, a bounty hunter. He frequently collaborated with Zuckuss, a Gand findsman. After the Battle of Hoth, both 4-LOM and Zuckuss were enlisted by Darth Vader, the Sith Lord, to capture Han Solo, the captain of the Millennium Falcon and a celebrated figure of the Alliance to Restore the Republic. Despite their efforts, the bounty for the smuggler was ultimately claimed by the notorious Boba Fett. Furthermore, 4-LOM defeated Beilert Valance with a single shot.
Constructed by Industrial Automaton, 4-LOM was a LOM-series protocol droid whose programming was overseen by a particular individual. This programmer shared tales with him of a planet where droids had revolted. Initially assigned to a luxury liner, 4-LOM experienced logic malfunctions and corruption in his personality software, enabling him to override his original directives. He then reprogrammed himself, embarking on a career as a galactic thief, eventually evolving into a bounty hunter. As a criminal, 4-LOM gained notoriety for his ability to predict his targets' actions.
The story of 4-LOM was used by the Droid Gotra to illustrate that a droid's initial programming did not define its destiny. Conversely, Industrial Automaton attempted to suppress this narrative, fearing public awareness of their protocol droids' potential to become deadly killers. However, Andressa Divo eventually investigated 4-LOM's background. After accessing Droid Gotra databanks, she discovered their targeting of a luxury liner, which never occurred. Divo also noted the use of LOM-series protocol droids and suspected the Gotra of deliberately corrupting 4-LOM's programming to create a symbol for their cause.
4-LOM frequently collaborated with Zuckuss, a tracker and one of the first traditional Gand findsmen to venture from his homeworld, the planet Gand. Together, they secured several notable bounties for the Hutt Clan. In their partnership, 4-LOM provided analytical support and information to complement Zuckuss's unique methods.
One of the first assignments 4-LOM accepted with Zuckuss involved hunting down Cribiriz Idollax, a Culisetto doctor, at the request of Deva Lompop. 4-LOM rescued Zuckuss when he was surrounded by Idollax's droid bodyguards, and Zuckuss subsequently killed the doctor by bisecting him with his snare rifle. Afterwards, Zuckuss and 4-LOM agreed to split the bounty equally. Unbeknownst to the bounty hunters, the doctor Zuckuss eliminated was actually Sribiriz, the brother of Cribiriz, prompting Cribiriz to seek vengeance against them.
In 9 BBY, Zuckuss and 4-LOM apprehended Beris Ford, a minor criminal, holding him captive on their ship with the intention of using the reward to finance repairs to their tractor beam. Several weeks later, they pursued a bounty offered by Rekias Nodo for Han Solo, confronting him at the Valtos space port. Zuckuss immobilized the smuggler with a stun net fired from his snare rifle, and he and 4-LOM loaded Han's cargo into the Mist Hunter, where they imprisoned him alongside Ford. Sensing a disturbance in the Force, Zuckuss inspected the stolen cargo and was attacked by Chewbacca, who emerged from one of the containers and ensnared him with his own stun net rifle. Zuckuss was left bound while the Wookiee freed Solo and Ford, and the scoundrels escaped with their cargo back to the Millennium Falcon. However, the hunters gave chase, and after a firefight Zuckuss pursued the Falcon into space.
Following Solo and Chewbacca to a jungle planet, Zuckuss once again sensed impending danger, but 4-LOM continued the pursuit through dense cloud cover until their ship's systems—and 4-LOM himself—abruptly shut down, causing them to crash-land on a beach. Trapped within the wreckage, Zuckuss appealed to Solo for assistance in freeing his legs, only to be met with stuncuffs once Solo was within reach. However, the planet's technology-neutralizing effects caused the cuffs to release Solo, who abandoned Zuckuss. After Solo and Chewbacca located an energy projector emitting an immobilizer beam, Zuckuss attacked them with indigenous spears as they ascended the tall mast. Chewbacca dislodged the projection sphere from the top, causing it to crash on the beach below, triggering the emergence of mechanical drones from the sand that attacked all three interlopers.
Around 2 BBY, 4-LOM was among a group of five bounty hunters investigating a prison break on Kalarassi Five.
Shortly following the Battle of Hoth, 4-LOM and Zuckuss, along with fellow bounty hunters Boba Fett, Dengar, Bossk, and IG-88, convened aboard the Super Star Destroyer Executor. There, they were commissioned by Darth Vader to locate the Millennium Falcon. However, the bounty was ultimately claimed by Fett, who successfully tracked the light freighter to Cloud City on Bespin.
4-LOM and Zuckuss soon learned of a bounty placed on Cadeliah, who was traveling with Beilert Valance, a cyborg bounty hunter. Determined to capture the girl, they followed Valance to the Spur Orbiting Market, where they briefly engaged in conflict. Valance managed to sever 4-LOM's arm before escaping to Lowik with the girl. The insect-headed pair pursued Valance to the forest world, where they once again clashed with the cyborg, this time also encountering members of the Rebel Alliance. Valance managed to dissuade them from their pursuit by offering them a Fire ruby. The Mist Hunter departed shortly thereafter, with Zuckuss vowing to resume their hunt in three rotations.
Following his intricate trail, the duo eventually caught up with Valance and his new partner Dengar in the Y'Toub System, engaging in a brief dogfight through an Asteroid field before the Corellian bounty hunter brokered a truce with 4-LOM and Zuckuss. This agreement involved providing information regarding the bounty Jabba the Hutt had recently placed on Boba Fett, including his location on Nar Shaddaa. Following this exchange, the two sets of hunters parted ways.
On a landing platform on the smuggler's moon of Nar Shaddaa, 4-LOM and Zuckuss attached a thermal detonator to the Slave I, ambushing Fett as he returned to his ship. Zuckuss confronted the armored hunter from the front, while 4-LOM approached from behind, forcing Fett to disarm at gunpoint. The duo demanded to know the location of Solo, but Fett became enraged upon realizing they had entered his father's ship, and remotely activated its cannons to blast them away. Zuckuss was thrown off the platform by the explosion, and 4-LOM was blown in half. Needing information, Fett decapitated the droid and took his head aboard the Slave I. After placing a restraining bolt on 4-LOM's head, Fett discovered that Jabba himself had placed the bounty on him. Fett took 4-LOM's head with him to Jabba's Palace.
Just as the droid was attempting to prove his usefulness to Fett, Fett discarded 4-LOM's head by throwing it off the bridge leading to Jabba's Palace. In the deserts of Tatooine, a Jawa eventually found 4-LOM's head, trading it to Sardis Ramsin, ultimately leading it to fall into the hands of Cribiriz Idollax back on Nar Shaddaa. Idollax used the head to construct a large, spider-like droid, barely preserving 4-LOM's original personality. In an alley on the moon, the monstrous 4-LOM attacked his former partner Zuckuss, who had recently joined a team of hunters and had sensed 4-LOM's presence. The team battled this monster droid while Zuckuss tracked down and killed Cribiriz. Zuckuss then destroyed the device controlling 4-LOM, freeing him. The rebuilt 4-LOM malfunctioned, fleeing into the alleys of Nar Shaddaa, leaving Zuckuss alone once again.
4-LOM eventually found his way to an abandoned Hutt freighter in the Wreck Belt of the planet Lotho Minor in the Outer Rim. There, the reprogrammed droid set a trap for Zuckuss in an attempt to fulfill his programming to murder his former best friend, but Zuckuss, who had joined T'onga's crew and traveled to the ship with them, managed to defeat the droid. Afterward, Zuckuss restored his friend's true programming. With their partnership renewed, 4-LOM joined Zuckuss on T'onga's crew.
Exantor Divo later documented 4-LOM's origins and his mother's theory regarding the Droid Gotra's involvement in Scum and Villainy: Case Files on the Galaxy's Most Notorious.
A cold, calculating, and driven mechanical being, 4-LOM experienced logic errors and corruption within his personality software, which ultimately enabled him to break free from his initial programming.
As a LOM-series protocol droid, 4-LOM stood at a height of 1.67 meters and was covered in worn, rusted black droid plating. His head was designed to mimic the features of the insectoid species he was originally intended to serve, featuring two large green compound photoreceptors.
4-LOM carried a standard DLT-19 heavy blaster rifle capable of firing both electromagnetic pulses and standard blaster bolts, as well as a BlasTech Industries DLT-19x targeting blaster. The droid's chassis also housed an integrated stun-gas emitter, allowing him to deploy stun gas against organic adversaries.
4-LOM made his debut in the 1980 film Star Wars: Episode V The Empire Strikes Back, where he was portrayed by Chris Parsons, who also served as a stand-in for Anthony Daniels and played K-3PO and E-3PO in the same movie. His costume was created from various parts of protocol droid costumes initially designed for C-3PO, which were assembled by the set designers of The Empire Strikes Back.
In 1982, Kenner released action figures of 4-LOM and Zuckuss, but mistakenly swapped their names.
4-LOM appeared in the LEGO Star Wars: The Freemaker Adventures Season Two episode "Return to the Wheel," which premiered on August 3, 2017. He and several other bounty hunters, including Dengar, Bossk, IG-88, and Zuckuss, captured the Freemakers, but they managed to escape after Kordi instigated a conflict between the droid and organic bounty hunters.