GekiFire (激獣王ゲキファイヤー), rendered in English as the "Herculean Giant GekiFire," is the second great battle robot of Juken Sentai Gekiranger — the powerhouse "Herculean Giant" that contrasts with the swift, dance-like "Beast-Fist Giant" GekiTohja. It is formed through the Juken Gattai (Beast-Fist Fusion) of the three Super GekiBeasts — GekiGorilla, GekiPenguin, and GekiGazelle — which the three core Gekirangers, Jan Kandou (GekiRed), Ran Uzaki (GekiYellow), and Retsu Fukami (GekiBlue), unlock after mastering the Extreme Qi (Kageki) technique in Episode 21. The burly GekiGorilla forms the head, arms, torso, and upper legs, while GekiPenguin and GekiGazelle build out the lower legs.

Compared to the nimble GekiTohja, GekiFire is markedly slower and less agile, but it more than makes up for it with raw strength, overwhelming durability, and sheer mass: roughly 60 meters tall and a hefty 3,600 tons. Its finisher is the crushing "Gan Gan Knuckle Otoshi" (Firm Knuckle Drop), a devastating hammering punch. Like GekiTohja, GekiFire can dock modularly with the Legendary GekiBeasts, transforming into specialized forms such as GekiElephantFire, GekiBatFire, and GekiSharkFire — each with its own weaponry and fighting style.

The DX toy is Bandai's (Japan, 2007) "DX Juuken Gattai GekiFire" — a wonderfully playful, motorized set. The three Super GekiBeasts combine into the complete robot, which performs the "Gan Gan Knuckle Otoshi" at the press of a button. It is loaded with individual gimmicks: GekiGorilla "walks" forward via battery-powered arms, rolls along on its wheeled feet, and even rights itself when it topples onto its back; GekiPenguin launches on its Jet Board straight through GekiGazelle. It requires 2 AA batteries (not included). The separately sold Legendary GekiBeasts attach one at a time to arm GekiFire with extra firepower.

In Power Rangers Jungle Fury the same machine is named the Jungle Master Megazord, formed from the Gorilla, Penguin, and Antelope spirits of the three Rangers in "Jungle Master Mode." Bandai America released the Jungle Master Megazord as a re-release of the Gekiranger form, making it compatible with the Japanese mecha — and it remains a coveted centerpiece for any Gekiranger / Jungle Fury display shelf.