The Radiation Creature is an antagonist who appears in Teen Titans. It appeared in the episode "Snowblind".
A Russian security force was tasked with a secret project to create the perfect soldier. The result was a disaster.
Captain Kovar had to isolate himself and discharge his radioactive power every day. However, he was unaware that there were microscopic cracks in the power conduits. Over time, the radioactive discharge leaked into a nearby river and formed into a creature with the same power. It began attacking anyone in the general vicinity and many blamed Kovar, instead.
When the Teen Titans investigated a distress call in the area, their T-Ship was blasted by the creature in zero visibility. Cyborg's geiger counter detected radiation levels off the scale. Undaunted, Starfire went alone to hunt the beast.
After the Titans followed a mysterious river of waste, Cyborg discovered it had the same isotopic signature as the creature. After regrouping in Kovar's compound, the creature attacked and was defeated by him. However, it absorbed several canisters of radioactive energy and went on a rampage to the city's power plant. Kovar then absorbed all of its power and dissipated the creature.