|This article is about a/an Mirror Monster in Kamen Rider Ryuki.|
Magnugiga appears as Zolda's Contract Monster. It resembles a Minotaur and is referred to as the Steel Giant as its size and heavy arsenal gives it the appearance of a mecha. Zolda uses multiple parts of Magnugiga for weaponry. However, unlike all the other Contract Monsters, Magnugiga doesn't seem to be able to move on its own, and is only a robot-like monster. As shown in the movie, Magnugiga never attacked Zolda after he quit being a Rider.
Magnugiga first appeared in Mirror World when Zolda used a Final Vent to destroy another Mirror monster and in the process barely missing both Ren and Shinji.
It also played a pivotal role in the downfall of Jun.
Most of the time however, Magnugiga because of his large size, was used as a shield by Zolda when he was not going on the offensive.
Magnugiga was destroyed by Asakura when it was kicked into the vortex on Genocider's chest.
- Destroyed by: Kamen Rider Ouja's Doomsday
- Animal Basis: Buffalo
- Height: 285cm
- Weight: 510kg
- Grip strength: 50t
- End of the World : Zolda's Final Vent; Zolda plugs the Magna Visor into Magnugiga's back and fires all of its arsenal at once.
Through the use of certain Advent Cards, parts of Magnugiga's body can be used by Zolda as weapons or other equipment.
- Giga Cannon (ギガキャノン Giga Kyanon): A pair of cannons derived from Magnugiga's legs. They mount on Zolda's back and fire over his shoulders. They are summoned with Zolda's first Shoot Vent card.
- Giga Launcher (ギガランチャー Giga Ranchā): A massive missile launcher derived from Magnugiga's arms combined together. It is summoned with Zolda's second Shoot Vent card.
- Giga Armor (ギガアーマー Giga Aāmā): A shield derived from Magnugiga's torso. It can also be used as a mount for the Giga Launcher. It is summoned with Zolda's first Guard Vent card.
- Giga Tector (ギガテクター Giga Tekutā): A pair of shoulder armor derived from Magnugiga's knees. Never used.
- Giga Horn (ギガホーン Giga Hōn): A gauntlet derived from Magnugiga's head. Never used.
- Magnagiga is never shown eating onscreen in the series, this may be due to it being a machine unlike the other contract monsters who seemingly are sentient beings.