Yamalgon (山怪獣ヤマグロン, Mountain Monster Yamaglon) is a mountain-lizard monster and an RP character used by Gallibon the Destroyer.
Yamalgon is a wild and chaos-loving monster and behaves like that of a bestial, savage animal.
Debut: The Revenge of Tsutabara Pt. 1
Yamalgon along with Umigaron were both summoned by Tsutabara to wreak havoc on Sapporo to assist the kaijin in their efforts to destroy the city and kill Sailor Fighter. Yamalgon and Umigaron showed up later to Sapporo and once they arrived, they roared and challenged Sailor Fighter, Earth Warrior Zeros and Kamen Rider Agito, also giving the five kaijin enough time to escape.
The Revenge of Tsutabara Pt. 2
Yamalgon and Umigaron were soon joined by Tsutabara's final kaiju pawn, Muchi in efforts to defeat Zeros, Sailor Fighter and Kamen Rider Agito. Yamalgon fought against Earth Warrior Zeros, by crushing some buildings and shooting explosive rocks at him. Earth Warrior Zeros managed to punch and kick through his explosive rock attacks though and even deflected a few of them back at Yamalgon.
Kamen Rider Agito joined up with Earth Warrior Zeros in taking down Yamalgon and the two ran at the kaiju. Yamalgon charged at them like a bull but was then hit by Kamen Rider Agito when he flew up and kicked at Yamalgon, hitting him with his double Flaming Rider Punch to the chest as well as Earth Warrior Zeros using his Iron Plasma Kick at Yamalgon's face. Yamalgon then let out one final roar before collapsing to the ground and exploded, killing him. Yamalgon was the second to last of Tsutabara's Sapporo kaiju pawns to die.
- Explosive Rocks: Yamalgon could shoot out small, but deadly rocks from his mouth that could expode on contact.
- Oddly enough, in Sailor Fight! he had Gyaos's roar.