Hammer Canth

Hammercanth (ハンマーカンス): A Mecha Gigan with a detectable head who was secretly installed under a factory so it would produce explosive balloons that are used for mass destruction. After Mason's scheme to break Green 2's fighting spirit fails and his base of operations exposed, Hammercanth enlarges to fight Bio Robo before its head was blasted to bits before the rest was destroyed.