Radioactive material used in the manufacture of nuclear power. In the Megakat Nuclear Plant’s main reactor room, they were kept contained within a glass cylinder filled with water. Twice, the reactor was broken into; first by the Creeplings, who stole the fuel rods for use in Dark Kat’s Doomsday Device, and then again by the lead Ci-Kat-A, who ate the rods in order to grow larger.