Galaxy Beast Warrior GingaiOh (星獣合体銀河獣士ギンガイオー, Seijū Gattai Ginga Jūshi Gingaiō) is the primary mecha of Seijuu Sentai Gingaman, formed by the union of the five Star Beasts (Seijuu). What sets it apart: these beasts are not built robots but ancient, living creatures – a central theme of the show and a detail that makes GingaiOh stand out among Sentai giants. Their human partners are the five Gingamen: GingaLeon (lion, fire) alongside Ginga Red, Gingalcon (falcon-dragon hybrid, wind) with Ginga Green, Gingarilla (gorilla, water) with Ginga Blue, Ginga Verick (wolf, thunder) with Ginga Yellow, and Gingat (cat, flowers) with Ginga Pink.

In the combination, GingaLeon forms the chest and head, Gingarilla makes up the hips and legs, and Ginga Verick and Gingat become the two arms. Gingalcon mounts onto the back as wings and can detach to become the Galcon Bowgun, a powerful crossbow-style ranged weapon. Later in the series, GingaiOh receives the golden armor of the black bull mecha Bull Taurus (Gou Taurus) to power up into Super Armor Shine GingaiOh.

The original DX toy was released by Bandai Japan as the "Seijū Gattai DX GingaiOh" (Chogokin, model GD-11). Standing roughly 280 mm tall, weighing about 1.6 kg, and packing substantial die-cast/Chogokin content, it is a hefty, old-school premium piece: the five Star Beasts can be played with individually and then assembled step by step into the robot, complete with the removable Galcon Bowgun. In the US, Bandai America released the same design in 1999 as the "Galaxy Megazord" for Power Rangers Lost Galaxy, where the beasts are called the Galactabeasts (Lion, Gorilla, Wildcat, Wolf, and Condor).

For collectors, the Japanese DX version is especially prized for its metal content and rich paint. In 2024, Bandai also revived the design in the Shokugan Modeling Project (SMP) as a highly detailed model kit – including a sleek Black Version in black and gold.