Taken from the Star Wars Wiki

Tor Vizsla was a male Human Mandalorian warrior and the first leaderof the Death Watch faction during the Mandalorian Civil War. He founded the splinter group following Jaster Mereel's ascension to Mandalore—leader of the Mandalorians—in 60 BBY in direct competition against Mereel's promulgation of the Supercommando Codex. While Mereel sought to root out what he saw as immoral banditry that had taken hold among the Mandalorians, Vizsla wished to continue their marauding ways, with the ultimate goal of starting a new Mandalorian War and conquering the galaxy in the name of his forefathers. To this end, he and his supporters waged war against Mereel's True Mandalorians for several years, with heavy casualties on both sides, until Vizsla was seemingly killed on Concord Dawn.

Vizsla and the Death Watch later reappeared on Korda Six where he managed to trap the True Mandalorians and kill Mereel as the Mandalore was betrayed by his second-in-command, forcing the True Mandalorians to retreat. After several more years in hiding, he laid another trap for the True Mandalorians and Mereel's successor, Jango Fett, in which a strike team of Jedi were manipulated into slaughteringVizsla's enemies for him. The only survivor of the battle, Fett was sold into slavery and spent several years aboard a spice transport. He managed to escape, however, and recovered a suit of Mandalorian armor from Galidraan. Fett then hunted Vizsla to Corellia where Fett destroyed Vizsla's ship, the Death Rattle, and fought Vizsla hand-to-hand on the planet's surface. Vizsla injected Fett with a poison to knock him out, but before he lost consciousness, Fett slashed open Vizsla's stomach. Attracted by the scent of blood, a pack of dire-catsattacked, killing and devouring Vizsla, leaving Fett to wake up the following day, unharmed.