Kassihm, a Kadas'sa'Nikto pirate and the captain of the M'hendosat, operated during the Galactic Civil War's initial stages. Shortly following the Battle of Yavin, he erred by attempting to plunder the Millennium Falcon's crew, an action that led to the destruction of his vessel and the demise of his crew at the hands of Rebellion operatives. Soon thereafter, Grand Moff 4-8C apprehended him. Kassihm then consented to aid the Imperials in their search for the droid B-1D4, a former passenger of the Falcon, all the while secretly planning his own escape from Imperial custody. Following an unsuccessful pursuit of the rebels and the rogue droid on Dweem, the Imperials eventually located B-1D4 at an Imperial detention facility on Merakai. With the droid successfully recovered, Kassihm understood that his usefulness to the Empire had expired and that his execution was imminent. Employing a droid disabler, he neutralized and disassembled 4-8C. Subsequently, he seized control of a ship, rescued the Falcon's crew, and enlisted with the Rebel Alliance.
In the opening years of the Galactic Civil War, Kassihm and his crew, known simply as Kassihm's Pirates, established themselves as a particularly infamous group of space pirates throughout the galaxy. Piloting their Predator-class warship, the M'hendosat, they routinely ambushed unsuspecting freighters, stealing their valuable cargo, selling their crewmembers into slavery, and dismantling the captured vessels to sell their components as scrap.
Some months after the Battle of Yavin, Kassihm and his crew came across the damaged Millennium Falcon while patrolling their usual routes. Never one to miss an opportunity for an easy score, the pirates swiftly boarded the Falcon, incapacitating the passengers with Bothan stun spores before confining them to the brig. Unbeknownst to the pirates, some of the rebels managed to avoid capture and initiated sabotage of various M'hendosat subsystems to create a diversion. The rebels then proceeded to reactivate the captured droids, including B-1D4, who employed the Heart of Steel virus stored within her memory to override the M'hendosat's security protocols and liberate the remaining prisoners. The escapees promptly began to wreak havoc throughout the ship, eliminating several members of Kassihm's crew as they gathered the necessary components to repair the Falcon's hyperdrive. Amidst the chaos, the M'hendosat's reactor core suffered critical damage, and the rebels narrowly managed to return to the Falcon and escape before the reactor reached criticality, resulting in the destruction of the M'hendosat and the demise of the remaining crew—with the exception of Kassihm, who managed to escape the ship in an escape pod just in the nick of time.
Shortly after his ship's destruction, Kassihm's escape pod was recovered by the Imperial vessel Zaker Besar, under the command of Grand Moff 4-8C. Aboard the vessel, he and the Skrilling droid merchant Dilrath were questioned by 4-8C and Burra Stone about the Millennium Falcon and B-1D4. Kassihm was able to verify that B-1D4 had been among the Falcon's passengers. Knowing that he would be executed for his past offenses, he managed to delay his fate by offering his services to the Imperials to assist in the droid's retrieval, an offer that 4-8C accepted. Utilizing data from the computer on Kassihm's escape pod, 4-8C determined that the Falcon was headed for Dweem and began to set a course.
Although orbital scans proved unsuccessful due to atmospheric storms, probe droids deployed to Dweem's surface detected a significant electrical signature, possibly originating from a power generator, leading the Imperials to believe that they had discovered a hidden Rebel base. Kassihm joined the Imperial reconnaissance team, which included Stone and 4-8C, on the planet's surface to search for the Rebels. On their way to the base, the team encountered a group of predatory Dweemons; large, spider-like creatures with camouflaged exoskeletons that rendered them nearly invisible against the terrain's frozen backdrop. Although the team managed to evade the creatures and reach the base relatively unscathed, their efforts proved futile. Instead of a new Rebel base, the facility was actually a derelict structure from the era of the Old Republic, defended by Iron Knights--sentient, Force-sensitive crystals housed within droid bodies. Kassihm and the Imperials returned to the Zaker Besar empty-handed, with no leads regarding B-1D4's location.
Infuriated that their mission on Dweem had been a failure, 4-8C planned to eliminate Kassihm. The Nikto objected, arguing that Solo would not have attempted any deception, as he likely did not expect anyone to have survived the M'hendosat's destruction. Realizing that The Heart of Steel must have commandeered the Falcon, 4-8C deduced that B-1D4 would return to Imperial Center, where she had served as a protocol droid for over a century, and where The Heart of Steel virus had been developed.
As fate would have it, the Heart of Steel had infiltrated Imperial Center's central computer system, disabling its defenses and allowing Solo and his companions to escape. Shortly thereafter, however, Darth Vader managed to capture the Falcon and its passengers on Cheeyoom Matee. Consequently, the Rebels and B-1D4 were apprehended and imprisoned in an Imperial detention facility on Merakai.
Kassihm, devising a plan to secure his own freedom, convinced 4-8C that B-1D4's presence in the Merakai prison would pose a significant risk to the Grand Moff; if the Merakai technicians were to probe the droid's memory, they would uncover 4-8C's unauthorized involvement with Heart of Steel's development. He offered to assist 4-8C by infiltrating the prison and retrieving B-1D4, as simply requesting the droid from the base commander would appear suspicious. The Grand Moff accepted the offer, but only on the condition that he and Stone would accompany Kassihm to ensure the pirate did not attempt to betray them.
Landing on Merakai in the Nikto ship Optitron, Kassihm and the Imperials trudged through the predator-infested swamp to reach Merakai Prison. Cutting through a grating, the group entered the prison through its sewage system. Choosing to impersonate Imperial inspectors from the Department of Punishment, the group located B-1D4 in the clutches of Merakai's droid torturer, who quickly recognized them as impostors. With the prison alarms sounding, the group seized the droid and freed all the prisoners, using the ensuing riot to conceal their escape. Temporarily allying with Solo and his friends, they managed to escape the prison and flee into the swamp on a stolen speeder. Solo opposed the Imperials' plans to take B-1D4, but relented after the Imperials promised not to pursue them if they surrendered the droid without a fight. With the operation complete, the group returned to the Optitron.
Following the completion of the mission, Kassihm realized that 4-8C would eliminate him, as he was no longer of any use now that B-1D4 had been retrieved. Recognizing that the only way to save his own life would be to join the Rebel Alliance, he devised a plan to turn the tables on the Grand Moff. Waiting until Stone was asleep in his stasis chamber, the Nikto retrieved a droid disabler that he had stolen from the Merakai armory. While 4-8C was examining the damaged B-1D4, the pirate quietly approached him from behind, readying his weapon. He did not go completely unnoticed, however, and 4-8C managed to turn around and draw a blaster just as Kassihm fired. As the deactivated Grand Moff collapsed to the floor, Kassihm realized that had he been even a split-second slower, he would have been killed. After dismantling 4-8C, the Nikto commandeered the Optitron and picked up Solo and his friends in the Merakai swamps, explaining what had become of 4-8C and expressing his interest in joining the Rebel cause. Deciding that he might be of use to the Alliance, having just "killed" a Grand Moff, Solo provided Kassihm with the coordinates to the nearest Rebel outpost. Kassihm's subsequent fate remains unknown.
Like the majority of space pirates, Kassihm was primarily concerned with two objectives: accumulating wealth and surviving long enough to enjoy it. Aside from himself, the only other individuals to whom he felt any genuine loyalty were his crewmen; however, he was more than willing to abandon them to their fate if it meant ensuring his own survival, as he demonstrated when the M'hendosat was destroyed. Although he ultimately joined the Rebellion after his ordeal with the Empire, his decision was likely driven more by a desire to shield himself from Imperial retribution than by any true sense of idealism.
Kassihm was conceived by Dave Wolverton for the Star Wars Missions game book, Star Wars Missions 13: Prisoner of the Nikto Pirates, where he served as the mission's main adversary. He reappears as a playable character in Star Wars Missions 14: The Monsters of Dweem and Star Wars Missions 16: Imperial Jailbreak.