Jabin is the main antagonist of "Caretaker", the first episode of Star Trek: Voyager.
He was portrayed by Gavan O'Herlihy, who also played Brad Wilson in Superman III.
Jabin was the first maje of the Kazon-Ogla sect, whose main camp was located on the Ocampa homeworld. He coveted the Ocampa's water supply, the only source of water on the planet, located in their underground city, but was unable to get past the force barrier surrounding the city. When the Ocampa girl Kes found a way out, Jabin captured and tortured her but she refused to tell him how to get through. He also had dealings with Neelix, who stole water from him.
When Voyager came to the planet, Neelix brought a number of crew to the Kazon camp and a hostile reception from Jabin. As a sign of good faith, Janeway demonstrated the ship's transporter, bringing down two large containers of water created with the ship's replicator. Neelix tried to get Jabin to release Kes in exchange for it but Jabin was more interested in acquiring Voyager's technology. Before negotiations could go any further however, Neelix pulled a gun on Jabin and then blew holes in the water containers, distracting the Kazon long enough for the group to beam back to Voyager with Kes.
Aware that the energy barrier was controlled from the Caretaker's array, Jabin took a group of ships into space to investigate it. There, they ran into Voyager and the Maquis ship they were allied with. Janeway tried to explain they only wanted to use the array to return to the Alpha Quadrant but Jabin refused to allow anyone else access to the Caretaker's technology and a battle broke out between the two groups of ships, resulting in a large Kazon carrier and the Maquis ship (whose crew had beamed to Voyager) being destroyed. Jabin sent out a call for reinforcements but Janeway had Voyager fire on the array and destroy it to prevent it falling into Kazon hands. Jabin withdrew without further fight after caustically informing Janeway she had made an enemy.
When the Kazon-Ogla reappeared the following season in "Initiations", they were led by Razik. Jabin's fate is unknown.