The MS-05 Zaku I is a Mobile Suit featured in the Mobile Suit Gundam: The Origin manga and OVA adaptation. It was the Principality of Zeon developed it from the MS-04 Bugu as part of its mobile suit project designed for Mass Production as well as actual combat against the Federation.
Technology & Combat Characteristics
According to the Director General of Anaheim Electronics, the MS-04 was completely over budget, and as a result the MS-04 was redesigned for Mass production, which is further refined into the MS-05 "Zaku". They were first put to use to prevent Trenov Y. Minovsky's defection to Federation: a Squadron comprised of 4 Zakus (piloted by the Mash, Ortega, Gaia and Char Aznable), alongside a MS-04 Bugu piloted by Ramba Ral, managed to force the Professor off road into Mare Smythii. They soon engaged 12 RX-77-01 dispatched by the Federation in an effort to rescue Professor Minovsky. Unfortunately, he was killed when a RX-77-01 wreckage fell upon him. The same battle also illustrated to the Federation of Tem Ray's proposal for a Mobile Suit that is geared toward for Mobile Suit Combat, leading to the approval of the RX-78 Gundam development Project.