Big Jak Targrim was the Riders of the Maelstrom's pirate leader, a male individual. He was a very large humanoid being, notable for possessing four arms.
By the time of the Galactic Civil War, Big Jak Targrim had risen to become the dominant chief of the infamous Riders of the Maelstrom. Leading his band of pirates, Targrim frequently engaged in battles to loot ships traversing the Maelstrom. To amplify his brutality, Targrim enhanced his genetic makeup through medical interventions, incorporating DNA "obtained" from various crime lords to project an even more intimidating presence.
Targrim's command resulted in total control of the Maelstrom until a competing pirate, Rodin Higron, cheated his way to victory in a sabacc game, winning the moon Oasis. This moon was situated within the Maelstrom, and Rodin Higron's pirates established their headquarters there. Enraged by Higron's incursion, Targrim conceived a plan to eradicate the opposing group. Targrim's crew hijacked the vessel known as the Kuari Princess and programmed it to crash into Higron's base. Regrettably for the Riders, operatives from the Alliance to Restore the Republic infiltrated the ship and disrupted Targrim's strategy.