(Teaching an Old Dog New Tricks)
The gladiator Destroid and systems testbed now known as Old Exterminator was manufactured in 2105 as a standard Duchy of Zeon MS-06J Zaku II Destroid. The J model was a ground attack variant of the Zeon forces' standard medium space Destroid, the MS-06F. A substandard Destroid (or, as the Zeon TO&E called them, "Mobile Suit") in terms of raw performance, the Zaku II was nonetheless popular among the Duchy's pilots, who liked it for its structural sturdiness (if not the durability of its armor), its ease of maintenance, and its low acclimation time requirements.
MS-06J #OK-0079 saw service in the One-Year War between the United Nations of Earth (with help from the Wedge Defense Force) and the Duchy of Zeon in 2106. Putting the lie to the old joke that the war ended because the Earth Defense Forces and WDF had destroyed every single piece of Zeon equipment, the Zaku survived the war and remained in the Zeon military inventory for more than four decades. It was sold, sans weapons, in 2149 to a shipping corporation, which used it as a cargo load lifter aboard superfreighters (a common fate for outmoded light and medium Destroids).
It is unknown when or precisely why 0079 was junked, but eventually the old machine wound up on Outer Rim 03F8, the home of the galaxy's biggest terrestrial junkyard. Here it might have been buried in the detritus of the Outer Rim's industrial expansion, lost forever in one of the lower strata of the scrapheap, if not for a quirk of fate which brought Skuld Ravenhair, the goddess of technology, to 03F8 in the late 2200s.
Skuld discovered 0079 in the course of an extremely hectic week on 03F8, and despite being extremely busy, she found time to take pity on the old Zaku and transport it to her workshop on Tomodachi. There it remained, among all the various things that Skuld had salvaged from various places (including several other items noted and tagged for recovery on the same trip to 03F8), until a century later, when Skuld gave the antique mobile suit to her young son Corwin as an educational toy.
Corwin took the Zaku apart, put it back together, and generally fooled around with it for several years, until graduating to bigger and better things. When he established his own workshop complex in the New Avalon defense tunnels, he took 0079 with him and used it for much the same thing its second owner had, as a glorified forklift.
In 2408, Corwin found himself simultaneously in need of two things: a suitable testbed for certain engineering concepts he had originally conceived during the original IPS Valiant galactic tour in the summer of 2406, and a Destroid in the medium tonnage class to use as a gladiator unit in a challenge match against Domon Kasshu, at the time the reigning champion on the popular battlesports game show Mobile Fighter G-Gundam. The Zaku's ease of maintenance and modification made 0079 the obvious choice, and over the space of a few days, the worn-out old workhorse was converted into a first-class war machine.
Gone was the underpowered micro-fusion reactor, replaced by the prototype for an entirely new power source devised by Corwin and based on the quasi-mystic Cephirean gemstone called gaolith. Gaolith, or "G-stone" as it is sometimes known, is the most powerful, stable natural source of Getter rays known to exist, and it forms the core of Corwin's new power source, the GS-Ride reactor system. Powered by a GS-Ride reactor and fitted with uprated motive power systems, partly scratch-built and partly salvaged from a wrecked RX-78GP-02 assault Gundam, the old Zaku found its power more than tripled. Other prototype systems being developed for the convertible aerospace robot series codenamed "Getter Robo" were also included in the rebuilt Zaku, which, along with the GS-Ride's energy type, gave the new model its type nickname, "Getter Zaku".
The reborn 0079 was dubbed Old Exterminator by Corwin's roommate Kozue Kaoru, after the battered, obsolescent, but sturdy and reliable P-40 figher plane featured in Colonel Robert L. Scott's God Is My Co-Pilot, an aviation memoir from Earth's Second World War. Despite the fact that Corwin had no time to uprate the standard Zaku weapons (except for the Heat Hawk; this was replaced by the prototype Getter Hawk, which would evolve into the Getter Robo's primary melee weapon, the Getter Tomahawk) nor to reinforce the machine's rather weak armor, Old Exterminator defeated and nearly destroyed Domon Kasshu's heavily modified RX-78 Gundam, Shining Gundam, in the New Avalon Battledrome.
Further modifications and upgrades are inevitable, as Old Exterminator continues to be used as a testbed for Getter Robo and other systems Corwin is developing. It is believed that the old Zaku now contains several systems devised by Corwin and Kasshu's crew chief, Rain Mikamura, when they rebuilt Shining Gundam with a second prototype GS-Ride reactor and other, unspecified improvements. However, these rumors cannot be substantiated, and so the specifications below are for Old Exterminator as it originally debuted in the Battledrome.
Model number: MS-06J-G1 Code name: Getter Zaku Unit type: Medium Destroid, Getter systems testbed/gladiator type Manufacturer: Ravenhair Systems, after Zeonic Company Operator: Corwin Ravenhair First deployment: January 25, 2408 Accommodation: Pilot only, in Big O-type cockpit in torso Dimensions: Head height 57 ft 9 in Weight: Dry weight 57 tons; max gross weight 80 tons Construction: Super-high tensile steel on monocoque frame Powerplant: Prototype GS-Ride Type One gaolith Getter Ray reactor Propulsion: Rocket thrusters, 100,000 lb thrust, augmented by prototype GW-1A "Zaku Wing" gravity-vector flight mantle Performance: Maximum flight acceleration 5.5 G Equipment and design features: Wraparound holotank cockpit visual environment; active sub-etheric sensors, range 5 mi Fixed armaments: "Getter Beam" engine energy projection through main optic Standard hand armaments: 120mm autocannon, drum-fed, 100 rounds per drum; 280mm rocket bazooka, 4-round magazine; Getter Hawk, reactor interface conduit through arm
(Entry format and base Zaku picture borrowed from Burke's All the World's Mobile Weapons, part of the most excellent Mecha Anime HQ.)