Joining S-S-Slithe and the other Mutant leaders on Third Earth to aid in the defeat of their enemies, the ThunderCats, and to capture the Eye of Thundera, the Reptillians bear many of the character traits of their leader. Ruthless, vicious and always eager to fight, the downfall of these evil warriors is their general lack of intelligence, which both allows S-S-Slithe to maintain his leadership over them and aids the ThunderCats in overpowering them. Nonetheless, they are formidable in sheer numbers, and, armed with a variety of weapons, are a threat that no ThunderCat should take for granted.