|This article is about a/an evil mecha in Chikyuu Sentai Fiveman.|
Formed from multiple pieces of construction equipment, it utilizes the power of the equipment combined with the mysterious energy of Vulgyre to empower its way through its enemies.
Originally existing as Gorlin #36 of the Enlarging Beast Gorlin, Garoa decides to experiment in order to try and attempt to retake the control of Zone by empowering the Gorlin with the strange, powerful energy within their spaceship headquarters Vulgyre in an attempt to regain captaincy from Chevalier. When releasing the Gorlin to face Fiveman, he merges it with several pieces of construction equipment, making it reborn as a mecha he pilots for combat. When using it, he easily crushes Fiveman and Super Five Robo, ripping their mecha apart while proving his superiority. Hoping to use this opening to his advantage, Garoa soon heads towards Magma Base to destroy it, only for Arthur to relaunch the base into space, taking advantage of Zone forgetting about its flight capabilities.
With Magma Base no longer on Earth, Garoa decides to use Big Garoan to destroy the newly rebuilt Newtown Elementary School on the day of its reopening. With Fiveman running low on options on how to deal with Garoa's threat, they decide to take a stand: standing on a tower near the school to divert Garoa's attention, they fire the Earth Cannon right into the cockpit of the mecha, opening it up. With the huge opening, Magma Base relands on Earth and Fiveman fire all weapons, destroying the mecha completely.
- Big Garoan is the only actual mecha (as opposed to a Sentient robot like the other Gorlin or Chevalier's Black Gorlin) created from an Enlarging Beast Gorlin