The Mutants of Plun-Darr were responsible for the destruction of Thundera, the homeworld of the THUNDERCATS. Hoping to finish the job, they pursued the fleeing survivors to Third Earth, where they quickly fell under the control of the ancient sorceror MUMM-RA. Known mutants include the lizard-man SLITHE, their leader; MONKIAN, the scout; the cowardly JACKALMAN; and VULTUREMAN, the Mutants' mechanic and the inventor of the robotic WOLFRAT.