|Voice Actor:||Toku Nishio|
Heroic Fighter Gamadone (ガマドーン Gamadōn?) is a brown-skinned monster with antennae and tentacled arms that electrocute enemies. He can also produce green slime on his tongue and spit it at opponents to form webs, as well as turning his right hand into a crab-like claw that emits glue and breathing fire. When not in battle he can reform his body. In Episode 4, he is injured by Metalder when the hero yanks out one of his internal organs and knocks him into the water. He survives and is seen fighting Hedogross Jr. in the Ghost Bank in Episode 15. In Episode 17, he kidnaps Mai to lure Metalder to him and tries to make love to her. He then battles Metalder again and is destroyed by his Laser Arm attack. Gamadone appears as an extra in the Metalder movie.