The GATX131 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 secondgeneration GATX machines, Calamity is built on the X100series frame and inherits GATX103 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 backmounted highenergy longrange beam cannons, a chestmounted multiphase energy cannon, 2barrel ram cannon equipped shield attached to the left arm and a handcarried plasmasabot bazooka.

Due to its TransPhase armor, a more energyefficient form of the Phase Shift armor, Calamity has a longer operational time than the first generation GATX machines and also has more energy for its powerhungry 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 GATX370 Raider Gundam when the latter is in MA mode to keep up with its flightcapable 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 GATX252 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 GATX machine, the Forbidden is designed for infiltrating and raiding enemy bases and to fulfil this role, it can transform into a "HighSpeed Assault Form" by flipping its huge backpack unit over its head. Like the other two second generation units, the Forbidden is equipped with TransPhase armor (TP armor). Its armaments consists of headmounted CIWS, forearmmounted machine guns, a handheld scythe and backpackmounted railguns and plasma cannon, both of which are usable only in "HighSpeed Assault Form".

As indicated by its model code, the Forbidden utilizes a X200series frame like the GATX207 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 GATX370 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 GATX machine to adopt the X300series frame used by the GATX303 Aegis Gundam. Compared to the Aegis, Raider has improved antimobile suit capabilities when in MA mode and its transformation system is greatly simplified. It is actually a variant of the GAT333 Raider Full Spec and maintains some of its predecessor's characteristics, like a MA mode specialized for flight and the two large fighter planelike 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 GATX131 Calamity Gundam). During battles, Raider often utilizes hitandrun attacks and has TransPhase armor like the other second generation machines. The Raider is armed with both energy and shellfiring 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.