Zeta Squad was a Dominion Marine Corps unit. It was stationed a warp-jump away from Roxara after the Brood War. They were equipped with old blue Confederate CMC-300 armor and composed of non-neurally resocialized personnel.
Five members of the squad were deployed to Roxara's moon to unknowingly participate in a live-fire exercise involving zerg changelings. They were chosen to see how well changelings could mimic non-neurally resocialized persons. The squad was destroyed in the process.