Ultra Galaxy Mega Monster Battle (ウルトラギャラクシー大怪獣バトル,Urutora Gyarakushī Daikaijū Batoru) is a Japanese tokusatsu drama in Tsuburaya's Ultra Series. It is the twenty-first series overall. This series started on December 1, 2007.
Thousands of years have passed since the events of Ultraman Mebius. The Organization known as Zata Astromical Pioneers (alternatively known as ZAP) has been founded and acts as a Freigther Transportation Group across the Galaxy. One of its branches, the ZAP SPACY and its crew are tasked with a mission to the research Planet known as "Boris" to rendezvous with its crew (whom have gone missing.) Upon arriving though, the ZAP SPACY quickly becomes stranded on the planet due to a SpaceTime Wave causing their ship to crash-land, where they learn that all human life on the Planet has been wiped out by a Monster Apocalypse.
While learning what's become of Boris, the team soon meets a mysterious youth named "Rei," who shows that he has the ability to control monsters when he uses the Monster Gomora to fend off a Red King! Rei however is also suffering from amnesia, with the only memories he possesses is that of a Giant that's trapped within a Mountainside. With a common enemy and wanting to escape from the planet, The ZAP SPACY and Rei join forces to fend off the Monsters that now inhabit Boris. Along the way, the Team meets a mysterious woman who appears to know more about Rei than he knows about himself, as well as a malicious Black Robot who's trying to hunt them down. Rei and the ZAP SPACY must now learn to work together if they are to survive in a dangerous world unlike the one they once knew, all while trying to unravel the mysteries to the Monsters' appearance, as well as Rei's past.
In addition to all the episodes in the series, an end segment of the episodes known as "Mega Monster Battle File" features Oki and Kumano showcasing the Monsters of their respective episodes (as the bandai toys to represent them) being displayed while tidbits of the Monsters are explained as well as Oki and Kumano's personal experiences with the Monsters.
Oki shows off Bemstar's ability to absorb energy through its Gorge (as well as reminiscing when it devoured a whole Space Station,) while Kumano congratulates a flattered Oki for helping them take the Monster down.