Zaid was a captain in the Carja military. He served the 13th Sun-King Jiran as the commander of one of the units tasked with conducting what were known as the Red Raids, raids on other tribes to abduct victims for human sacrifice. Zaid's cruelty in conducting these raids was second only to Helis, Jiran's champion. However, he was killed many years after the raids ended by the daughter of a Nora whom he had murdered during a raid carried out by his unit.
During the Red Raids, Zaid's unit attacked the Nora settlement of Mother's Rise. In the course of the raid, Zaid mutilated and murdered the father of two Nora siblings, Nakoa and Yan, before Nakoa's eyes. Some time later, Sun-King Jiran was overthrown by his son Avad. As the new Sun-King, Avad promoted peace and reconciliation with the tribes his father had terrorized, while expelling the troops who had been complicit in the Red Raids from the Carja military. Zaid's entire unit was expelled, but Zaid himself escaped this fate by covering up his involvement and adopting a tolerant and peaceful persona in public. With the end of Carja military aggression, Zaid became a prefect of the Carja outpost Daytower on the Carja/Nora border, stoutly claiming innocence of any war crimes if he happened to be recognized by travelers. In secret, however, Zaid started a slave ring with the men of his former unit. He would direct vulnerable members of other tribes, such as those traveling alone, to abandoned outposts staffed by his slavers; they would then abduct the travelers to sell at slave auctions.
Zaid's atrocities caught up with him when Nakoa, who had left the Nora Sacred Lands in order to exact vengeance on him, found him at Daytower and attacked him. As usual, he feigned innocence. Ostensibly to show that he did not hold her supposedly misguided attack against her, he had her released instead of detained. His actual motive, however, was to capture her as a potential victim for his slave ring. To that end, he had his men seize her soon after she left Daytower, traveling alone and unsupported with nobody around to see or help her. Like all his victims, he had his men take her to a remote, abandoned Carja outpost and imprison her there, striking and kicking her every time he went there as retribution for attacking him.
Some time after, however, he was confronted by the Nora Brave Aloy, who was searching for Nakoa on behalf of Yan and the siblings' aunt, Solai. When Aloy asked him about Nakoa and his part in the Red Raids, he again feigned innocence. As with Nakoa, he saw Aloy as a potential victim. To set up her capture, he told Aloy that he had heard reports of a young woman being abducted by bandits at Lonesome Rock, a remote Carja outpost manned by his men. He did this in the expectation that she would go there in search of Nakoa, and his men would overpower and seize her when she got there.
Aloy did indeed go there in search of Nakoa, but killed the men when they attacked her. Finding a trail that evinced the transportation of slaves from the outpost, she followed it to the abandoned outpost where Nakoa and the other victims were being kept. Aloy freed Nakoa and the other victims, but Zaid went to the location with more of his men just as Aloy freed them. He and his men attacked Aloy, but she killed the men and incapacitated him. Unable to stand or fight, he was helpless as Nakoa approached him with a spear from one of his fallen men, and ran him through with it.