Gubi Gubi was the second monster of the UFORobovGreatMazin under the command of Captain Barandos, deployed immediately to assist Barandos and Great Mazinger. Its UFO Mode was bright red in color. The robot mode was blue, yellow, grey and black, with a humanoid torso standing on a support spine, with long spikes for feet. It had a cone head with red eyes and yellow spikes. It sport it Shell as arms, connected to smaller shell that sported spikes on its side: Gubi would use these for both shield and weaponry that would detach to through at an enemy, these serve as wheels so it could be mobile on the ground.

After the Destruction of Jin Jin, Gubi Gubi was deploy to help Barandos fight Grendizer, and the two were able to pin Grendizer down, though Gubi loses its left arm in the process, until Koji (having escape Prison) contacts Daisuke, providing him information of Great's weakness, been the back where the wings fold, would cause a shutdown, though automatic repairs would commence afterwards. In its attempt to hit Grendizer, Barandos almost hit Gubi with debris from Great's weapons. Grendizer then takes its chance and shuts down Great with Double Boomerang. Barandos abandons Great and orders all forces to retreat. During the pull back, Koji takes his chance to escape the ship and takes control of Great Mazinger and fights Gubi while Grendizer deals with the Mothership.

The two have a brief standoff, but Koji dispatches Gubi Gubi with an Atomic Punch, then rendezvous with Daisuke to deal with the Mothership.