The RX-78GP02A Gundam "Physalis" (aka "Physalis", GP02A) is the second of four mobile suits in the Gundam Development Project featured in Mobile Suit Gundam 0083: Stardust Memory. Originally belonging to Earth Federation, it was stolen and piloted by Delaz Fleet's ace pilot, Anavel Gato.

The Gundam "Physalis" was initially supposed to be an assault-use, heavy mobile suit similar to the Principality of Zeon's Dom series. This was eventually dropped and replaced by the goal of being the most powerful MS to date. Inadvertently, this led to the Physalis being armed with the most deadly weapon available, a nuclear warhead. The second research division of Anaheim Electronics in charge of developing the Physalis was mainly comprised of former Zeon engineers, so Zeon-based technology is strongly incorporated into the mobile suit.

Due to the jamming effects of Minovsky particles, guided precision nuclear weapons were rendered unusable and because of this, strategic nuclear warheads that served as a deterrent and as a means of retaliation were useless. Thus, the only viable choice is a tactical nuclear warhead meant for use in combat situations with friendly forces nearby and tend to have a lower explosive power than the strategic nuclear warheads. However, this is not always the case, as the Mk-82 warhead used by Physalis has an explosive power comparable to a strategic nuclear warhead despite its tactical classification.

The Physalis uses an atomic bazooka to launch the Mk-82 warhead, but due to the bazooka's relatively short firing range, the mobile suit's armor was designed to be both heat and shock resistant to protect itself from the nuclear blast. Similarly, to ensure the pilot's safety when the Physalis operates near the blast area, its cockpit was designed to be more impact resistance and with higher pilot survivability than normal mobile suit's. Instead of a Core Block System, the Physalis utilized a spherical cockpit block that was first proposed at the end of the One Year War, and it is protected by multiple layers of composite armor and cushioning material.

The cockpit itself is also filled with powerful neutron moderators to better protect the pilot from the harmful effects of being near the blast area. In case of emergency, the cockpit can be ejected with explosive bolts. The Physalis also carried a large shield that contains a powerful cooling system. This shield also stores the barrel of the bazooka when the weapon is not in use. Other weapons of the Physalis included two head-mounted Vulcan guns and two beam sabers stored in the side skirt armor.

Despite its bulky appearance, the Physalis is highly maneuverable and can hover when operating under gravity. This is thanks to the newly developed high-output generators installed in the mobile suit, as well as the pair of 'Flexible Thruster Binders' mounted on the shoulders that house multiple thrusters. Overall, the Physalis is a powerful mobile suit even without its nuclear weapon. It was also rumored to be designed to work in tandem with its brother unit, the RX-78GP01 Gundam "Zephyranthes".

While nuclear weapons were abhorred due to their destructive effects, the leaders of the Earth Federation Forces viewed them as a necessary evil to maintain its superiority in the post-One Year War period. In fact, the Principality of Zeon had deployed or attempted to deploy nuclear weapons on multiple occasions during the war, even after the signing of the Antarctic Treaty. Furthermore, the Antarctic Treaty only prohibited the "use" of nuclear weapons as opposed to the "development" and "storage" of them. Thus, the Physalis was technically not a violation of the treaty.

There were also some that viewed the Antarctic Treaty as a wartime treaty that was defunct in the post-war period, but there were others that thought differently. Aiguille Delaz of the Delaz Fleet, a Principality of Zeon remnant group that eventually stole the Physalis, was an example, albeit a radical one. He considered the treaty still in effect as he did not recognize the peace treaty signed at the end of the One Year War. He then used this supposed violation by the Earth Federation Forces to rationalize the capture and use of the Physalis and its nuclear weapon.