Origin
Pre Vizsla, a member of the Vizsla clan, followed in the footsteps of one of his relatives, Tor Vizsla, and became the leader of the Mandalorian Death Watch. During his time as leader, he committed terrorists acts against his own people to inspire fear and show that the warrior class of Super-Commandos should again be the ruling party. Though the current Mandalorian Duchess Satine sought the aid of her long-time friend/love interest, Obi-Wan Kenobi, who after many battles with Pre and the Death Watch, eventually captured him.
Later as the Clone Wars raged on, Mandalore, a neutral planet, fell prey to a group of pirates and gangsters under the leadership of Darth Maul and Savage Opress, Pre Vizsla was freed by the brothers and offered leadership of his people in exchange for his loyalty.
Death
Pre Vizsla was not exactly loyal to Darth Maul, and planned to kill the Nightbrothers, but Maul had anticipated this, and looked to Mandalorian culture for a precedent to challenge Pre Vizsla without the interference of his troops, Maul found just that, and challenged him to an honorable battle to the death. Maul came out victorious, sending Pre to fall to his death at the close of their battle.