Swamp Hippo King is the king of the swamp hippos. He and his army were forced to attack the swamp villagers when Twin Masters placed two chaotic teeth in his mouth. Becuase Dog King and band of dogs had recently abandoned Big Green, they became prime suspects for perpetrators of the attacks. After First Squad and Wu Song traveled to the swamp and the dogs are proved innocent and are rescued by Mystique Sonia. She and Yaksha were then pinned down by the Swamp Hippo King tooth bullets only to be saved by Wu Song. When the chaotic teeth are removed by Wu Song, Swamp Hippo King turns back into peace lover and he decides to join Big Green.