Tor Vizsla, a Mandalorian warrior of the Human male persuasion, holds the distinction of being the inaugural leader of the Death Watch faction during the tumultuous era of the Mandalorian Civil War. Following Jaster Mereel's rise to the position of Mandalore—chieftain of the Mandalorians—Vizsla established this breakaway group in 60 BBY, directly challenging Mereel's promotion of the Supercommando Codex. Mereel aimed to eradicate the rampant immoral banditry he observed within the Mandalorian ranks, but Vizsla championed the continuation of their plundering practices, harboring ambitions of initiating a fresh Mandalorian War and seizing control of the galaxy in honor of his forefathers. Consequently, he and his adherents engaged in warfare against Mereel's True Mandalorians for a number of years, resulting in significant losses on both sides, until Vizsla met his apparent demise on Concord Dawn.
Subsequently, Vizsla and the Death Watch resurfaced on Korda Six, where he successfully trapped the True Mandalorians and killed Mereel, who was betrayed by his second-in-command, compelling the True Mandalorians to withdraw. After remaining hidden for several more years, he orchestrated another ambush for the True Mandalorians and Mereel's successor, Jango Fett, manipulating a Jedi strike team into slaughtering Vizsla's adversaries on his behalf. Fett, the lone survivor of the conflict, was sold into slavery and endured several years aboard a spice transport. He eventually escaped, retrieved a set of Mandalorian armor from Galidraan, and pursued Vizsla to Corellia, where Fett annihilated Vizsla's vessel, the Death Rattle, and engaged Vizsla in hand-to-hand combat on the planet's surface. Vizsla injected Fett with a poison to incapacitate him, but before succumbing to unconsciousness, Fett slashed open Vizsla's abdomen. Drawn by the scent of blood, a pack of dire-cats descended, killing and consuming Vizsla, leaving Fett to awaken the following day, unharmed.
Within the ranks of the Mandalorian Clan Vizsla, stood Tor Vizsla, a male Human warrior. In the year 60 BBY, Jaster Mereel assumed the mantle of Mandalore, asserting authority over the Mandalorian clans that still adhered to their traditional warrior culture. He introduced his Supercommando Codex as a novel ethical benchmark for all Mandalorians, advocating honorable conduct as highly-compensated mercenaries rather than conquerors. Moreover, he aimed to dispel the public image of Mandalorians as amoral killers. Vizsla, however, contested this reformation, coveting the title of Mandalore for himself. He championed the notion that the Mandalorians should revert to their origins as conquerors, asserting their inherent right to wage a second war for dominion over the galaxy, and obliterate the detested pacifist regime of the New Mandalorians. Amassing like-minded Mandalorian hardliners to his cause, he spearheaded a violent coup against Mereel's supporters, establishing a breakaway faction known as the Death Watch, and modifying his clan sigil to symbolize the movement.
After dispersing Mereel and his forces on Concord Dawn in 58 BBY, Vizsla's troops hunted them across the planet. Upon discovering a young Jango Fett laboring in his father's fields, Vizsla interrogated the boy while his accomplice held him at gunpoint. Learning that Jango's father had provided refuge to Mereel, Vizsla subjected the Journeyman Protector to brutal interrogation. When he refused to cooperate, Vizsla instructed one of his men to place a blaster to his son's head, threatening to kill the boy unless the elder Fett relented. Before any harm could befall her son, Jango Fett's mother fatally shot the Death Watchman holding him. The elder Fett urged him to flee, and the boy dashed into the fields with several of Vizsla's men in pursuit. As they closed in on the young Fett, he was rescued by Mereel and his remaining followers. Hearing the ensuing firefight in the fields, Vizsla commanded his men to set them ablaze while they murdered Jango's parents and abducted his sister. Confident that the fire had vanquished his nemesis, the Death Watch settled in for two days of rest and recreation in a nearby town to celebrate their triumph. There, they were ambushed by Mereel and the remnants of his army. During the battle, Vizsla sought refuge inside his tank, and Jango affixed an explosive to its underside. When the smoke cleared, Mereel searched the wreckage and, although no body was discovered, Vizsla was presumed dead.

However, Vizsla was encountered alive in 52 BBY, though bearing extensive scars from the explosion. By luring the True Mandalorians into an ambush on Korda Six, the Death Watch decimated more of Mereel's forces with assistance from the native Kordans. Vizsla emerged on the battlefield aboard a tank and personally gunned down Mereel when the Mandalore was deserted by his own second-in-command, Montross—who sought leadership of the Mandalorians for himself. When the True Mandalorians retreated, leadership passed to Jango Fett, who vowed to hunt down Vizsla once and for all.
When the governor of Galidraan consented to relay information about the Death Watch's whereabouts to Jango Fett in exchange for his Mandalorians quelling a rebellion in 44 BBY, Vizsla devised yet another trap for his adversaries. He coerced the governor into requesting assistance from the Jedi Order, alleging that the Mandalorians were massacring political activists. When Fett met the governor at his castle, Vizsla attempted to assassinate him, firing upon Fett from behind a curtain where he concealed himself with several of his men. Fett retreated, leaping out a nearby window and activating his jetpack, but Vizsla disabled it with a shot from his blaster pistol, sending Fett plummeting to the ground below.
Confident that the trap had succeeded, Vizsla and the Death Watch departed to fabricate evidence of civilian casualties, while the Jedi, led by Master Dooku, arrived at the Mandalorian camp and eliminated every Mandalorian except for their leader. Jango Fett was handed over to the governor, who promptly had him sold into slavery.

After two years aboard a spice freighter, Fett orchestrated his escape during a pirate assault. Returning to Galidraan, he retrieved his armor and held the governor at gunpoint, demanding to know Vizsla's whereabouts. The governor informed him that the Death Watch had departed Galidraan only two days prior, heading for Corellia. Above Corellia, Vizsla occupied a prominent position on the bridge of his ship, the Death Rattle, attended to by a Twi'lek servant when his troops detected an incoming projectile on the ship's sensors. Fett employed a starfighter to disable the Death Rattle's engines while he himself stormed the bridge by shattering the main viewport. As the ship began to disintegrate, Vizsla fled toward the escape pods, instructing his men to abandon ship. Fett pursued him, and they skirmished briefly before descending to the planet aboard a pod of their own.
The two men engaged in a savage fistfight, evenly matched, until their brawl carried them over a cliff and into a river. Upon washing ashore, Vizsla injected Fett with a poison that rendered him near-lethargic. Before he could deliver the final blow, however, Fett slashed open Vizsla's stomach with a pair of blades ejected from his gauntlets. As Fett slipped into unconsciousness, the Death Watch leader was attacked, killed, and devoured by a pack of dire-cats who were drawn by the scent of his blood but ignored Fett completely.
Vizsla and his followers were largely condemned by the Mandalorian community long after his demise. Boba Fett, Jango Fett's clone son, believed that his father's enduring legacy for the Mandalorians was the destruction of the Death Watch. While the True Mandalorians remained defeated, the Death Watch persisted in secret for decades, resurfacing years after Vizsla's death.

Pre Vizsla, another member of Vizsla's clan, assumed clandestine leadership of the breakaway faction while serving as the governor of Concordia, Mandalore's moon, and publicly supported Duchess Satine Kryze of Kalevala. Under Pre Vizsla's command, the Death Watch initiated a terrorist bombing campaign during the Clone Wars against Kryze's New Mandalorians, who controlled the city of Sundari, and conspired with the Confederacy of Independent Systems to reconquer the entire planet. Their scheme was thwarted when Jedi Master Obi-Wan Kenobi arrived on Mandalore to investigate rumors that Kryze was assembling a secret army to fight for the Separatists, discovering Pre Vizsla's hidden base and uncovering his true allegiances in the process.
By the conclusion of the Clone Wars, leadership of the Death Watch had passed to Lorka Gedyc, who advocated cooperation with the new Galactic Empire as a means of restoring the Mandalorians' strength. Former members of the Cuy'val Dar—a group of training sergeants handpicked by Jango Fett to train the Clone commandos of the Grand Army of the Republic's—Dred Priest and Isabet Reau actively recruited for the Death Watch in the city of Keldabe. Priest remarked to fellow Cuy'val Dar member Mij Gilamar that Gedyc had improved the Death Watch from its state under Tor Vizsla.
By 1 ABY, Vizsla's movement had largely faded into legend. Another man, styling himself "Overlord" of the Death Watch, had relocated the group's headquarters from Concordia to the forest moon of Endor. There, they continued to operate in secret, having allied themselves with Black Sun, until a band of spacers in the employ of Imperial Commander D'krn infiltrated their bunker, killed Viba, and obtained a sample of his blood to create a new batch of stormtroopers.

Count Dooku characterized Vizsla as a barbarian, an apt description given his brutal and vicious methods. On Concord Dawn, he ordered his troops to massacre the young Jango Fett's family and later permitted them to plunder a local town. When he orchestrated the Battle of Galidraan, he directed the planet's governor to inform the Jedi that Fett's Mandalorians had been slaughtering women and children. When the governor protested the lack of evidence, Vizsla vowed to fabricate it.
Vizsla was also narcissistic and egomaniacal. He resented Jaster Mereel for usurping the title of Mandalore and fueled his ego by proclaiming that he and his followers would conquer the galaxy as their Mandalorian ancestors had intended. His followers were merely sycophantic thugs held together by the force of his charisma.
Vizsla donned a suit of black Mandalorian armor adorned with a red cape and his clan sigil on the shoulders. His gauntlets were equipped with various weapons, including a wrist rocket, flamethrower, whipcord launcher, and poison injector. He also employed various blaster rifles and pistols in combat, as well as a tank on at least two occasions. He also commanded a personal starship, the Death Rattle. Furthermore, he was known to possess the Darksaber.
Haden Blackman, a Star Wars writer, conceived the character of Tor Vizsla for the four-part comic series Jango Fett: Open Seasons, released on May 1, 2002, shortly before the premiere of Star Wars: Episode II Attack of the Clones. Initially known simply as "Vizsla," he was eventually given a first name on August 18, 2009, in The Essential Atlas by authors Jason Fry and Daniel Wallace.
The name Tor translates to "justice" in Mando'a.
Dave Filoni, the supervising director of Star Wars: The Clone Wars, applied the name Vizsla to Pre Vizsla, the primary antagonist of the three-part Mandalorian story arc of The Clone Wars: Season Two, as a reference to the Expanded Universe material, also incorporating the name and symbol of the Death Watch. The Clone Wars Character Encyclopedia later connected the two characters by retconning the Death Watch insignia into the symbol of Clan Vizsla.