Mysterious earthquakes were hitting Cross World City. The Troopers began to investigate, which brought them closer to Grimlord's underground digging operation. Fistbot (voiced by Scott Page-Pagter), a brown boxer mutant armed with flying punching gloves and a powerful upper body armor, was assigned to stop them so Grimlord could dig to the Earth's core. Defeated by Ryan when Ryan scanned him and discovered his legs were his weakness; Ryan tackled/attacked him by going for his legs and threw him into a nearby lake, but didn't destroy him, leaving Fistbot only to be weakened. In the "Defending Dark Heart" saga, Fistbot was seen participating in the Dark Heart hunt where he was shot by Dark Heart in battle which caused him to fall over and explode. After the destruction of Grimlord's dungeon, Fistbot survives as a mere head. He attacks Ryan and is soon destroyed afterward, inflicting pain on the weakened Ryan as well. Fistbot fits the category of Decimator's army.