Mechagodzilla is an alien mecha created by Toho that first appeared in the 1974 Godzilla film, Godzilla vs. Mechagodzilla. In Terror of Mechagodzilla, the "2" in its name after it is rebuilt comes from the fact that it is the second Mechagodzilla.
Appearance:
ShodaiMekagoji
Mechagodzilla is a robot that resembles Godzilla from the 1960s through 1970s. The suit used for it was known as ShodaiMekagoji (初代メカゴジ).
The original Mechagodzilla in Godzilla vs. Mechagodzilla has short and stubby finger missiles, a metal piece with three bolts on the hand plate, a less defined and prominent shoulder frill, one orange button each on the chest and above the crotch, a bottom-half pentagon underneath the chest cannon, two circular pieces coming from the chest canon, smooth grooves that runs along the back feet, the knee plates gets smaller as they go towards the back of its legs, a smooth and solid tail blade, the plates on the tail are smooth and run straight across, and red "MG" initials on its arms that stands for "Mecha Godzilla".
GyakushuMekagoji
The GyakushuMekagoji (逆襲メカゴジ) refers to the rebuilt Mechagodzilla from Terror of Mechagodzilla has longer finger missiles, one big metal piece on its hand plate, a more defined and prominent shoulder frill, one silver button on the chest, one silver button underneath the chest cannon and two silver buttons above the crotch, a triangle underneath the chest cannon, two lightning-like pieces coming up the chest, sharp spurs that stick out of the back of the feet, the knee plates get really small and thin half way and goes around the back, a smooth and solid tail blade with three big bolts in it, the plates on the tail are V-shaped, and blue and orange "MG2" initials on its arms that stands for "Mecha Godzilla 2", thus giving it the name Mechagodzilla 2 (メカゴジラ2).
The Millennium incarnation is featured in two films: Godzilla Against Mechagodzilla and Godzilla: Tokyo S.O.S. and is referenced as Kiryu (機龍, Kiryū), derived from Kikai Ryu (Japanese for "machine dragon") or "Kōryū" (Japanese for steel dragon), Kiryu's legal name is simply "Mechagodzilla," while his official designation in the films is "MFS-3," which is short for "Multipurpose Fighting System Type-3".
The Mechagodzilla (メカゴジラ Mekagojira) of the [url=https://myanimelist.net/anime/33783/Godzilla_1__Kaijuu_Wakusei]AniGoji[/url] continuity was the fourth Mechagodzilla in the Godzilla film series, and the first and so far only Mechagodzilla in the Reiwa era of films. This Mechagodzilla made its first appearance in the novel, Godzilla: Monster Apocalypse, a prequel novelization to the 2017 film, [url=https://myanimelist.net/anime/33783/Godzilla_1__Kaijuu_Wakusei]Godzilla: Planet of the Monsters[/url], which detailed its origins and original fate. Mechagodzilla then appeared in the 2018 prequel novel, Godzilla: Project Mechagodzilla, where more of its history and abilities were run down. It made a cameo appearance in [url=https://myanimelist.net/anime/33783/Godzilla_1__Kaijuu_Wakusei]Godzilla: Planet of the Monsters[/url] and its manga adaptation, where its failed use was briefly detailed. Mechagodzilla went on to have its first major film role in the 2018 film, [url=https://myanimelist.net/anime/36816/Godzilla_2__Kessen_Kidou_Zoushoku_Toshi]Godzilla: City on the Edge of Battle[/url] as the main antagonist.
(Source: Wikipedia & godzilla.fandom)
Character information provided by MyAnimeList
