GAT-X131 Calamity Gundam, GAT-X252 Forbidden Gundam, GAT-X370 Raider Gundam

The GAT-X131 Calamity Gundam is a Mobile Suit introduced in the anime Mobile Suit Gundam SEED. It is piloted by "Biological CPU" Orga Sabnak.

One of three second-generation GAT-X machines, Calamity is built on the X100-series frame and inherits GAT-X103 Buster Gundam's artillery attack concept. It can also be used to provide support from the rear and is armed with several powerful range weapons, but it completely lacks any close combat weaponry. Its armament consisted of two back-mounted high-energy long-range beam cannons, a chest-mounted multi-phase energy cannon, 2-barrel ram cannon equipped shield attached to the left arm and a hand-carried plasma-sabot bazooka.

Due to its Trans-Phase armor, a more energy-efficient form of the Phase Shift armor, Calamity has a longer operational time than the first generation GAT-X machines and also has more energy for its power-hungry beam weapons. With the powerful thrusters installed around the body, it can hover over deserts or bodies of water easily. However, as it lacks true flight capability within the atmosphere, it often has to ride on top of GAT-X370 Raider Gundam when the latter is in MA mode to keep up with its flight-capable sister units when moving to the combat zone. In this configuration, Calamity uses Raider much like ZAFT suits use the Guul subflight lifter. The control system of the Calamity is very complex and its customized OS can only be used by the "Biological CPU".

The GAT-X252 Forbidden Gundam is a Mobile Suit introduced in the anime Mobile Suit Gundam SEED. It is piloted by "Biological CPU" Shani Andras.

A second generation GAT-X machine, the Forbidden is designed for infiltrating and raiding enemy bases and to fulfil this role, it can transform into a "High-Speed Assault Form" by flipping its huge backpack unit over its head. Like the other two second generation units, the Forbidden is equipped with Trans-Phase armor (TP armor). Its armaments consists of head-mounted CIWS, forearm-mounted machine guns, a handheld scythe and backpack-mounted railguns and plasma cannon, both of which are usable only in "High-Speed Assault Form".

As indicated by its model code, the Forbidden utilizes a X200-series frame like the GAT-X207 Blitz Gundam, and as such it is also equipped with special equipment. One special equipment is the "Geschmeidig Panzer" energy deflection armor installed in its two massive shields. This equipment can deflect any range beam attacks that hits it, making the Forbidden virtually invulnerable to these attacks. Coupled with the fact that the shields themselves also have TP armor, the Forbidden is thus well protected from most beam and physical attacks. In addition, the "Geschmeidig Panzer" also allows the Forbidden to move underwater with ease, even though it is not specifically designed for aquatic use.

Another special equipment is the magnetic field generators installed on the railguns, they allow the bending of the plasma cannon's beam, making the attack harder to evade. Due to the powerful thrusters in the backpack, which is actually a specialized flight unit, the Forbidden can fly in the atmosphere and is one of the rare mobile suits to be capable of both aerial and aquatic combat without any additional equipment.

The GAT-X370 Raider Gundam is a transformable Mobile Suit introduced in the anime Mobile Suit Gundam SEED. It is piloted by "Biological CPU" Clotho Buer.

The Raider is a transformable mobile suit and the only second generation GAT-X machine to adopt the X300-series frame used by the GAT-X303 Aegis Gundam. Compared to the Aegis, Raider has improved anti-mobile suit capabilities when in MA mode and its transformation system is greatly simplified. It is actually a variant of the GAT-333 Raider Full Spec and maintains some of its predecessor's characteristics, like a MA mode specialized for flight and the two large fighter plane-like main wings that give it full atmospheric flight capabilities. These wings also boost Raider's turning capabilities and acceleration speed on earth and in space, as well as allow it to serve as a subflight lifter unit for carrying other mobile suits (usually the GAT-X131 Calamity Gundam). During battles, Raider often utilizes hit-and-run attacks and has Trans-Phase armor like the other second generation machines. The Raider is armed with both energy and shell-firing weapons (with some of them being usable only in flight mode) and uses the "Mjolnir" Spherical Breaker, a wire tethered mace, as its handheld weapon.