Slyssk, a Trandoshan male, was a starship pilferer who found himself entangled in the Mandalorian Wars alongside Jedi Zayne Carrick and Marn Hierogryph.
During the Mandalorian Wars, a significant conflict of the time involving the Galactic Republic and the nomadic Mandalorian warriors, lived Slyssk, a Trandoshan male. Despite hunting being a central aspect of Trandoshan culture, Slyssk felt ill when participating, leading him to pursue a different path as a starship thief. He became a member of the Raff Syndicate, where he acquired ship-stealing skills. However, he soon grew disillusioned with the pirate organization and was expelled before mastering the art of piloting the stolen vessels.

Later, Marn Hierogryph, a Snivvian black marketeer, and Zayne Carrick, a Human Jedi Padawan fleeing the Jedi Covenant after being wrongly implicated in the Padawan Massacre on Taris, sought Slyssk's expertise to secure transport off the planet Ralltiir. Hierogryph orchestrated Slyssk's theft of a ship, promising 9000 credits for its delivery to Pad 223 at midnight. The target was the Little Bivoli, a Quartermaster-class supply carrier owned by a crew of freelance provisioners supporting the strained supply lines of the Republic Navy. As the owners prepared to refuel, Slyssk commandeered the Bivoli and clumsily flew it to Pad 223, damaging several lampposts during the landing. Upon seeing Hierogryph and Carrick, he initially hid inside the ship but eventually emerged, demanding ten times the agreed-upon price, citing Hierogryph's reputation. When negotiations stalled, Carrick used the Force to drop a damaged lamppost on Slyssk. Hierogryph intervened, saving the Trandoshan, an act that prompted Slyssk to swear a life debt, designating the Snivvian as his ghrakhowsk, and offering the ship for free. The original crew's arrival and attempt to reclaim their vessel forced the trio to escape aboard the Bivoli. Reaching orbit, they were hailed by the Courageous, the flagship of a Republic fleet, and ordered to join a hyperspace jump to Serroco, where a confrontation with the Mandalorians was imminent.
The Bivoli landed at Camp Three, a Republic Army staging area on Serroco. Hierogryph transformed the ship into an alternative to the army commissary. Slyssk became the chef, and his Bivoli Tempari became popular among the soldiers, establishing the Bivoli as a favored spot in Camp Three. Carrick, foreseeing a Mandalorian attack, urged Slyssk and Hierogryph to leave the planet and went to the Courageous to warn the fleet. The following day, coinciding with Carrick's prediction, Slyssk prepared exceptionally delicious Trandoshani flatcakes using an improved technique. Despite Carrick's pleas via comlink, Hierogryph kept the Bivoli open until the afternoon, finally preparing to leave after a siren signaled the arrival of Mandalorian ships in the system. Slyssk then revealed that the ship lacked sufficient fuel due to his incomplete refueling during the theft. Panicked, the Trandoshan grabbed his ghrakhowsk and boarded a departing troop transport. Overpowering the guards, Slyssk piloted the ship to safety. Unbeknownst to him, the transport's crew was asleep, and Slyssk had inadvertently saved half a battalion of Republic soldiers. On Chandrila, the Ministry of Defense fabricated a propaganda narrative, casting Hierogryph and Slyssk as Captain Benegryph Goodvalor and Commander True, Goodvalor's "trusty Trandoshan sidekick," respectively.
Later, the Ithorian bounty hunting Moomo Brothers, acting on behalf of Jervo Thalien, chairman of Lhosan Industries, hired the duo for a mission on Taris. As Hierogryph led the Taris Resistance against the Mandalorian Neo-Crusaders who had invaded the planet, Slyssk and Dob Moomo extracted Carrick from the beleaguered Arkanian Legacy and brought him, along with Jedi Knight Alek, Demagol, a Mandalorian scientist disguised as Rohlan Dyre, and Jarael, an Arkanian Offshoot, back to Taris. Upon arrival, Carrick disembarked from the Moomo's ship, Moomo Williwaw, to meet Hierogryph, leaving Slyssk and the others to find a safe orbit to wait.
Around the time of the Mandalorian occupation of Taris, a 40,000-credit bounty was placed on Slyssk for piracy, as advertised in The Adjudicator Special Report: The Colonies. Following the failure of the Taris resistance, Slyssk and the Williwaw escorted Sector Constable Noana Sowrs's children to safety on Alderaan before rushing to rescue Carrick and Hierogryph from Jebble, a Rakghoul–infested planet. Slyssk remained with the crew during their journey to Odryn, where part of the group retrieved Sith artifacts from a Jedi Covenant storehouse to expose the Covenant.

The Williwaw's arrival at Coruscant, home to the Jedi Covenant's base and the Jedi Order, was met with a formation of Republic warships. An attempt to breach the blockade led by the Swiftsure](/article/swiftsure(inexpugnable-class)) resulted in heavy damage to the ship, necessitating a change of plans. Slyssk purposefully crashed the Williwaw into the Swiftsure's hangar, then stole a Conductor-class shuttle and, using the chaos as cover, transported Carrick and Hierogryph to the planet below. Overcome by a panic attack after landing, Slyssk was given credits by Hierogryph and sent to a hotel to recover. Following the successful exoneration of Hierogryph and Carrick, the Jedi Covenant was dismantled, and the pair resolved to combat injustice. While Carrick took a leave, Hierogryph tasked Slyssk with acquiring a new starship to replace the Williwaw. Unaccustomed to legal purchases, the Trandoshan nervously bought what was described as "a gem of a ship." However, the Hot Prospect turned out to be a dilapidated Calipsan 560 gem mining ship infested with mynocks. As retribution for the deception, Hierogryph used his authority as Slyssk's ghrakhowsk to make the Trandoshan clean the ship.
The crew of the Hot Prospect, minus Carrick, aimed to scam the planetary rights auction at the Metellos Exchange. Their scheme was foiled by Nunk Plaarvin, the Chevin manager of the Raff Syndicate-backed Metellos Exchange, resulting in the capture of Jarael and Demagol. Carrick rejoined Hierogryph and Slyssk aboard the Hot Prospect, and they devised a plan to rescue their friends. Slyssk, dressed as a Raff captain with mynocks serving as kneepads, confronted Plaarvin, intimidating him into fleeing to the recently decimated planet, Jebble. With Plaarvin gone, Jarael and Demagol were freed, and the Prospect departed Metellos 3 to investigate the disappearance of the Chancellor Fillorean.
Slyssk bypassed the Chancellor Fillorean's hatches to gain entry, only to discover the crew dead, except for two individuals: Toki Tollivar, a Bimm Sith Acolyte in disguise, and his companion droid. Slyssk provided the Bimm with water and food, but when left alone, Tollivar attempted to strangle him using the Force. Demagol performed an emergency tracheotomy, saving the Trandoshan's life, before Tollivar was exposed as a Sith and killed. The Hot Prospect then traveled to the swoopdueling tournaments at Jervo's World, where Slyssk remained medicated on the ship under Demagol's care, recovering from Tollivar's attack.
The Hot Prospect's next stop was Wor Tandell, where Slyssk arranged for the use of a plantation's facilities through a friend. Jedi Knight Alek, now known as Malak, met Jarael at the camp, and Slyssk prepared a meal for the group. Following a confrontation between Malak and Demagol, the crew departed to investigate The Crucible slaving operation. Slyssk, continuing his ship-cleaning duties, discovered a microtag attached to Exar Kun's lightsaber, which Demagol had extracted from nullification resin.
Arriving in the Koornacht Cluster, Carrick and Jarael, posing as Crucible traders, confronted Sariyah Budan, the head of the Sungrazer cooperative, threatening to undercut her mining operation by collecting thorilide crystals themselves. To bolster their claim, the rest of the Prospect's crew began harvesting crystals, with Slyssk mastering the use of several mining systems on the Calipsan 560, including the particle accelerator. The Trandoshan also suggested using the ship's centrifuge to process the crystals more efficiently. However, Dace Golliard, the Crucible Fleet Captain, arrived aboard the Gladiator to suppress the disruption as Carrick and Jarael began freeing enslaved workers. With the Crucible ship bombarding the Prospect's attitude thrusters, Slyssk was unable to maneuver the ship to retaliate. Improvising, the crew used xenoboric acid, a drill, and a crane arm to attack the Gladiator. To escape, Carrick instructed Slyssk to disable the inertial compensators while he jammed the centrifuge. The resulting momentum caused the mining ship to spin violently, allowing it to jump to hyperspace.

In an attempt to locate the Crucible's base, Carrick, under the guise of "Carth Kamlin," a stranded Republic Navy officer, was taken to Volgax. Jarael eventually discovered Carrick's location after the Crucible abandoned Volgax, but a disagreement over Jarael's past led to her and Demagol leaving the Hot Prospect. Meanwhile, on Coruscant, Rohlan Dyre—believed to be Demagol—awoke from a coma. Carrick, Hierogryph, and Slyssk were summoned to Coruscant to testify at Demagol's trial for his numerous crimes. Before the trial, Carrick prompted Hierogryph and Slyssk to recount their experiences on Serroco. Similarly, T1-LB, a bulk-loading droid traveling with Carrick, revealed that Demagol had switched places with Dyre, ensuring the latter would be tried for the former's crimes. After freeing Dyre, Carrick sent Slyssk to retrieve Mandalorian armor for Dyre and escort Shel Jelavan, a co-founder of Carrick's Rogue Moon Project, back to the Project's base, where they planned to rescue Jarael. Slyssk piloted the Hot Prospect on a final mission that resulted in Dace Golliard's capture. Golliard revealed the location of Jarael and Demagol: the planet Osadia. On Osadia, Carrick and Dyre rescued Jarael, while Demagol was killed, ending his dangerous experiments. Days later, the group parted ways, with Slyssk working as a waiter and chef under Hierogryph at the Goodvalor's Little Bivoli restaurant on Coruscant.