The Harbinger was a large tank transport used by the Confederacy of Independent Systems during the Clone Wars.
The Harbinger was a experimental CIS starship. It was designed to invade and conquer planets. It's cargo bay houses multiple squads of tanks and walkers. It's defensive weaponry slows down attacks on itself. It's equipped many ion cannons and a prismatic turbo laser thar fires mutiple beams simultaneously.
The Harbinger was first deployed on Alaris Prime. There it destroyed by General Kenobi and Commander Skywalker with their fighter tanks.