The MS-14A Gelgoog was a "high-efficiency general purpose mobile suit" mass produced and used by Zeon forces. Originally, the Gelgoog was being developed as the MS-11, but at the time the RX-78-2 Gundam was rolled out in the feddie forces, the original Gelgoog project was cancelled. It was later reinstated, as the MS-14, with the new goal being the use of energy cap based weaponry. 25 prototype Gelgoogs (under the model number MS-14S) were built, after which the actual MS-14A went into development, roll out, and deployed in the field.
The Gelgoog was intended to replace the aging MS-06F Zaku II as the front-line unit of Zeon, and was as powerful (if not more so) than the Gundam mobile suit used by the Earth Federation. It was built to be able to handle both terrestrial and space combat, and was armed with a large beam rifle and a twin beam sword. Complementing this was a large shield.
Unfortunately, the deployment of the Gelgoog in December of UC 0079 was too late. Only 165 units were produced and in combat by 31 December UC 0079, at the battle of A Baoa Qu.
For those of you who don't know (and there seem to be many), this is info coming from the first Mobile Suit Gundam TV series. If you want better context, I'd be pleased if someone would msg me with what I should have.