Grinder is a Hanuman themed Phantom Beast Warrior, who held the spirit of the Monkey. He wielded a staff in battle. His staff could control fire. He serves as the main antagonist of the episode "Maryl and the Monkeys".
Grinder was one of Phantom Beast Warriors. He used the battle style of Hanuman (the mythical monkey king, the character of Chinese mythology) and also hold the spirit of the monkey. He wielded a staff in battle. His staff could control fire. During the first Beast War, Grinder fought, alongside his allies, against Pai Zhuq Academy and Dai Shi Clan. He was destroyed along with other Phantom Beasts. However, Crystal Eyes, that possessed the power to resurrect them, were left behind. In the twenty-third episode, Jellica used Crystal Eyes and revived Phantom Beasts and ordered them to serve her and help her destroy Dai Shi. But Scorch, Snapper and Whiger betrayed and destroyed her and joined Dai Shi. Grinder was summoned by Scorch along with other Phantom Beast Warriors.
In the twenty-ninth episode, Grinder aided Camille in stealing the primate duplicate formula from the scientist Maryl Snyder. Camille tested formula on Grinder and then sent him to attack Ocean Bluff. Grinder attacked the city and encountered Jungle Fury Rangers. He used his ability gained from formula. He created decades and hundreds of his clones and they fought Power Rangers. Dominic went after Maryl, while other rangers battled Grinder clones. Rangers called Spirit Rangers to help them. Despite clones were weak, but they were many and heroes were hard to battle them even with help of Spirit Rangers. Camille ordered Grinder not to show up. And side effect of formula made Grinder itchy. Grinder ran and hid on the lake. However, Scorch arrived and told Grinder that Camille changed her mind and fight the rangers. Dominic arrived and took down Grinder with Rhino Morpher Claw. Then Grinder grew. Rangers formed their Megazords to battle him. Grinder fought Jungle Master Megazord, Wolf Pride Megazord and Rhino Pride Megazord. He attacked Zords with flames, but Dominic used the rhino super freeze attack to freeze him on ice and grinder was then destroyed by the Jungle Master Stampede Formation.
In the final battle Grinder was revived by Dai Shi, but was destroyed, along with Unidoom, by Theo.