Jaster Mereel was a male Human born on the Outer Rim world of Concord Dawn. For years, Mereel served as a Journeyman Protector, one of the planet's respected lawkeepers, until the day when his strong morals led him to kill a corrupt superior officer. Charged with murder, Mereel was exiled from Concord Dawn, going on to join the Mandalorians. An accomplished soldier, Mereel's prowess in battle earned him the respect of his supercommando peers, and he eventually became Mand'alor, the leader of all the Mandalorian clans, and the Al'Ori'Ramikade—"Commander of Supercommandos." As Mand'alor, Mereel instituted a new guideline for Mandalorian behavior known as the Supercommando Codex in which he asserted that the Mandalorians who wished to fight would simply be highly paid soldiers, and should conduct themselves as honorable mercenaries.
Mereel faced opposition to his reforms both from the peaceful New Mandalorian faction, and the more dangerous Death Watch, a violent splinter group formed by the followers of Mereel's rival, Tor Vizsla. A civil war broke out between the Death Watch and the supercommandos loyal to Mereel, the early years of which saw Mereel's return to his home planet, where he saved the life of a local farmer's son—Jango Fett—when the Death Watch attacked the boy's home. Taking Fett in following the death of his family, Mereel raised the boy as a his own son until the fateful Battle of Korda Six. Ambushed by the Death Watch and betrayed by his second-in-command, Montross, Mereel was killed by Vizsla. His body was carried back to the Mandalorians' landing zone by Fett, where Montross was exposed as a traitor and Fett succeeded his adoptive father as the new Mand'alor, in accordance with what Mereel would have wanted.
Jaster Mereel was a male Human, born on the agricultural world of Concord Dawn in the Outer Rim's Mandalore sector. As an adult, Mereel served as a Journeyman Protector—one of his homeworld's respected lawkeepers—until he was driven by his strong moral code to kill a corrupt superior officer. Mereel was subsequently charged with murder, and exiled from Concord Dawn. At some point after, Mereel joined the Mandalorians; an accomplished soldier, Mereel's martial prowess earned him the respect of his peers. Around 60 BBY, Mereel had attained the rank of Mand'alor, the traditional leader of the Mandalorian clans. Having noticed many Mandalorians' dissatisfaction with the widespread savagery that had become prevalent in certain warrior circles, Mereel hoped to hold the Mandalorians to a higher standard of behavior. As Mand'alor, Mereel instituted the Supercommando Codex, a new behavioral guideline influenced by Mereel's own moral ideals, in which Mereel decreed that any Mandalorians who wished to fight would be merely highly paid soldiers, and should conduct themselves as honorable mercenaries. It was around this time that Mereel had some dealings with the Regent of Mek va Uil, acting as both Mand'alor and Al'Ori'Ramikade—"Commander of Supercommandos." During this interaction, Mereel informed the regent of his views on what it meant to be a mercenary, and why they were deserving of respect.
However, Mereel's ideas were not unanimously accepted throughout the Mandalorian community. By this time, many Mandalorians had joined the peaceful movement of the New Mandalorians, a reformist political faction formed in the aftermath of a devastating conflict with the Galactic Republic centuries earlier. The New Mandalorians had moved away from the traditional warrior ways, denouncing the old warrior codes, and believed that the best opportunity for Mandalorian survival and prosperity would come through being peaceful, neutral, and tolerant. Further dissension came in the form of a number of a amoral Mandalorians who resented Mereel for his attempts to rein in their enjoyed lifestyles of unaccountability. These malcontents rallied to a Mandalorian soldier named Tor Vizsla, and therein formed a splinter group known as the Death Watch with Vizsla as their leader, under the pretense of returning the Mandalorians to their ancient roots as conquerors and raiders with the goal of instigating another war of conquest. Though the Death Watch's goals were quite opposite to the New Mandalorians', they could neither support Mereel's faction of loyal supercommandos—now calling themselves the "True Mandalorians"—for despite his reforms, any act of Mandalorian violence was fundamentally against what the New Mandalorians stood for. Mereel was pressured by Mandalorian hard-liners such as Montross to destroy the Death Watch, and civil war soon broke out between Mereel's True Mandalorians and the Death Watch. The New Mandalorians kept to their ideals of pacifism and non-violence, rejecting both groups and remaining out of the conflict that came to be known as the Mandalorian Civil War.
In the year 58 BBY, Mereel returned to his homeworld as the Mandalorian Civil War spilled onto Concord Dawn. Hunted by the Death Watch after a lost firefight, Mereel and his men were forced to rely on the kindness of the Journeyman Protector who'd replaced Mereel, a man by the name of Fett. He offered them refuge on his family's farm, and brought them food in the fields. However, the Death Watch captured Fett's young son, Jango, and attempted to use the boy, in addition to a brutal beating, to force the Journeyman Protector to reveal the location of Mereel and his True Mandalorians. Fett would not give in, and a chaotic firefight erupted when Fett's wife attempted to save her husband and son. Both Fett and his wife were killed, although Mereel stepped in—giving up his cover—in order to save young Jango's life. As the Death Watch set fire to the field Mereel and his troops had fled into, Jango led them to an irrigation pipe that would take them safely away from the blaze. Mereel regrouped his forces in a nearby town and laid in wait until the Death Watch arrived, at which time he sprang an ambush. With the Mandalorians firing on the Death Watch troops, Jango placed an explosive charge on the underside of the armored speeder Vizsla rode into the town upon. The tank exploded, although Vizsla escaped. As the battle came to a close, Mereel located Jango standing over the body of the Death Watch soldier who'd murdered his parents. Praising the boy's courage, Mereel decided to take Jango with him as the Mandalorians departed Concord Dawn, and he eventually came to consider the boy his son.
By 52 BBY, six years after the battle on Concord Dawn, Mereel believed the Death Watch to be finished. With the Death Watch gone, Mereel now led his True Mandalorian supercommandos as a mercenary force, and it was in that capacity that they traveled to the planet Korda Six. Contracted by the Korda Defense Force, Mereel and his men had been hired to extract a rookie security team pinned down under fire by a force of local hostiles. Kordan intelligence suggested minimal resistance; the natives had no formal army and were poorly armed. Considering the mission "easy credits," Mereel divided his men into three teams: Vertigo Company, an aerial unit utilizing jetpacks under Mereel's second-in-command, Montross, "Jango's Grunts," which would provide cover fire and hold the extraction zone, under the command of a now teenage Jango Fett; and Headhunter Company, Mereel's own unit, charged with reaching the recovery site and extracting the security team. As the Mandalorians boarded their ships, Mereel spoke briefly with Jango, asking the boy to make him proud.
On the approach to the planet's surface, Mereel's ships took heavy damage from ion cannon fire, forcing most to make the best of rough crash-landings. The "minimal resistance" estimated turned out to be vastly inaccurate, and almost immediately, the Mandalorians came under heavy fire. Mereel was helpless as numerous soldiers fell victim to enemy blasters, and it wasn't long until the Mand'alor called for them to abort the mission and retreat. Montross refused to comply, unwilling to have a retreat on their record, and pushed forward, only to fall prey to a grenade blast that left him wounded and in need of rescue himself. That rescue came from Mereel, who shot and killed no fewer than three enemy Kordan before angrily reiterating his orders for a retreat. At the same time as Jango and his team stumbled upon a Death Watch ambush, Vizsla arrived on the battlefield in a four-wheeled tank. Mereel berated Montross' foolhardy actions as the reason they were in such a situation, swearing to have him ejected from his mercenary crew if they survived the battle. Vizsla was determined to see that they would not survive, launching a wrist rocket that injured Mereel, although Montross avoided it using his jetpack. As Vizla opened fire with a laser cannon, Mereel called to Montross for an airlift. But Montross had decided he would no longer take orders from Mereel and turned his back on the Mand'alor, leaving him to die alone on the battlefield while he returned to the other Mandalorians. Mereel soon fell to fire from Vizsla's tank, though Jango tried desperately to reach him. It was in Jango's arms that Mereel succumbed to his injuries.
Montross attempted to take over leadership of the Mandalorians upon his return to camp, claiming that Mereel was dead and that Jango had perished trying to save him. However, Jango returned to the camp, carrying with him his adopted father's body, and exposing Montross as a liar and a traitor. As Montross slipped off into exile, Jango succeeded Mereel the new Mand'alor, just as the other Mandalorians believed Mereel would have wanted, having previously chosen Jango as his successor. Jango went on to avenge Mereel by killing Vizsla on Corellia, and later Montross on one of the moons of Bogden.
Following Mereel's death, Jango took ownership of Mereel's personal starship, an AIAT/i transport which he renamed Jaster's Legacy in Mereel's honor, and treasured for years to come. Jango also used Jaster Mereel's name as a pseudonym during his life and career as a bounty hunter, as a means of honoring his adopted father. Jango's cloned son, Boba Fett, would do the same during his own career as a bounty hunter, following his father's death at the hands of Jedi Knight Mace Windu in the First Battle of Geonosis, along with his brief tenure as a Journeyman Protector on Concord Dawn. Boba would unwittingly follow in his grandfather's footsteps, becoming a Journeyman Protector only to be exiled from Concord Dawn after killing a superior officer. In Boba's case, however, the officer in question was a man by the name of Lenovar whom he had greatly respected, and whom Boba killed after Lenovar raped Boba's wife, Sintas Vel. The use of Mereel's name by both Jango and Boba contributed to rumors that Mereel was still alive and operating years after his actual death, and some even believed that the inverse was true—that "Boba Fett" was actually an alias being used by Mereel. Boba also recovered Mereel's armor, and he wore Mereel's distinctive sigil on his armor's breastplate. The knowledge of the circumstances surrounding Mereel's betrayal and death kept Boba wary for years after, even in the presence of allies.
One of the Grand Army of the Republic's Null-class Advanced Recon Commandos, a clone trooper designated Null-7, was given the name "Mereel" by the Mandalorian Cuy'val Dar training sergeant, Kal Skirata. Following the Clone Wars and his desertion from the Republic's Grand Army, the good-humored ARC lieutenant went on to become a Mandalorian, just as his namesake.
Jaster Mereel was a man of strong morals and a rigid ethical code. Highly respected as one of Concord Dawn's Journeyman Protectors, Mereel was unable to suffer the corruption of his superior officer and killed him, an act that pushed him toward a new life as a Mandalorian. An extraordinary soldier, Mereel's combat prowess won him the respect of his Mandalorian peers. During a time when many Mandalorians had fallen into disreputable brigandage, Mereel's strong ethic drove him to become Mand'alor and institute a reform that would change the way the Mandalorians conducted themselves for years to come. Mereel's moral code would also not allow him to stand by when a young Jango Fett was threatened by the Death Watch, giving up his cover to rescue Jango from the more numerous Death Watchmen. Mereel was a confident but pragmatic commander, proud of the skill he and his troops possessed, but was unwilling to let that pride influence his decisions, such as whether to retreat in battle. On a personal level, Mereel was a direct speaker who spoke plainly and was unafraid of bluntly casting blame where he felt it was due. At the same time, he cared for his comrades and especially for Jango Fett, whom Mereel took in when the boy had become an orphan and raised like a son until his untimely death. Mereel was also proud to be a mercenary, and believed it to be a noble profession worthy of respect.
Jaster Mereel wore traditional Mandalorian armor of a metallic-gray color, with red shoulder plates and red trim around the visor of his rangefinder-equipped helmet. On the left shoulder, Mereel bore the custom Mythosaur skull-inspired insignia of the True Mandalorians, and his chest plates were adorned with a yellow-painted, four-sided diamond. Mereel also wore a red cape, heavy combat boots, and a brown multi-pouched utility belt with his armor, but did not wear or use a jetpack in the field. During his life as a Mandalorian soldier, Mereel utilized a short-barreled blaster rifle that supported the attachment of a combat knife beneath the muzzle, in addition to two blaster pistols which he kept in two holsters around his thigh plates.
Jaster Mereel was originally the true identity of Boba Fett in the novella "The Last One Standing: The Tale of Boba Fett," a fact that was repeated in Fett's entry in the The Essential Guide to Characters. But when Star Wars: Episode II Attack of the Clones was released in 2002, its depiction of Fett's childhood on Kamino as a clone of Jango Fett relegated the other backstory to non-canon status. However, the four-part comic Jango Fett: Open Seasons retconned the character of Jaster Mereel to be a different individual, the mentor of Fett's father, Jango. It was also revealed that both Jango and Boba Fett occasionally used Mereel's name as an alias, thus saving the story from being apocryphal. Daniel Keys Moran, author of "The Last One Standing," was unaware of the retcons surrounding Jaster Mereel until a 2018 interview, given that he hasn't followed much of the franchise's newest products.
Apart from his appearance in Jango Fett: Open Seasons, Mereel was referenced again in the Star Wars novel Republic Commando: Triple Zero by author Karen Traviss, wherein Null ARC trooper N-7 was named Mereel, after Jaster; the clone Mereel appeared in every subsequent entry in the Republic and Imperial Commando series. Traviss' fourth Republic Commando novel, entitled Order 66, featured a quote from Jaster Mereel as the opening for the novel's tenth chapter, and the series' next installment, Imperial Commando: 501st, featured several references to Jaster Mereel and the events seen in Open Seasons.