The Steel Starbeast GigaPhoenix (鋼星獣ギガフェニックス, Kōseijū GigaFenikkusu) is one of the two Koutetsu Seijuu – the "Steel Starbeasts" – from Seijuu Sentai Gingaman, joining the Gingaman as a powerful ally from Episode 29 onward. It was once the living, phoenix-like Starbeast GingaPhoenix, mortally wounded when the space-pirate Balban destroyed its homeworld. Its remains were rebuilt into a steel mecha – alongside the heavy-hitting GigaRhinos and the enormous carrier GigaBitus – to fight beside the team's main robo, Gingaioh.

At rest, GigaPhoenix exists as five separate GigaWings stowed in the front hangar of the giant GigaBitus. On command they are launched from GigaBitus' mouth and lock together through the "Beast-Sky Fusion" (獣空合体, Juukuu Gattai) into a humanoid robot. GigaPhoenix is the fast, agile flier among the Steel Starbeasts: where GigaRhinos charges in head-on, GigaPhoenix soars and flanks its foes. It wields the Giganic Boomerang as a melee weapon or hurls it as an energy-charged projectile, and fires a blue energy beam from its chest. Teamed with GigaRhinos, it unleashes a swirling energy cyclone. In Power Rangers Lost Galaxy, GigaPhoenix is known as the Stratoforce Megazord.

The DX toy was released by Bandai Japan as the "Juukuu Gattai DX Chogokin GigaPhoenix" (獣空合体 DX超合金 ギガフェニックス) – the "Chogokin" name pointing to its quality die-cast content. All five GigaWings physically dock together into the robot, just as on screen. Bandai America reissued the same mold as the "DX Stratoforce Megazord" for Power Rangers Lost Galaxy. Collectors should watch for the notorious Gold Plastic Syndrome: the gold-tinted plastic parts grow brittle and crack over the years, so clean, intact examples are highly prized. For a smaller, break-proof alternative, the Mini-Pla model-kit line offers a lovingly detailed build.