A radbug was a genetically-designed variant of a butterbug that was created specifically to consume, purify, and excrete radioactive material. The goal was to concentrate the material in mounds, making it easier to collect and remove from the environment.
Sizes were seen as ranging up to approximately 12 centimeters long, but were extremely variable. A radbug was beetle-like in form and had glossy wing carapaces, but no wings underneath. The carapaces, head, and legs were deep shimmering purple, with a bright yellow trefoil on top. The trefoil glowed more brightly the more radioactive the radbug was.
The attractiveness proved problematic, as it resulted in the very poisonous bugs being stolen by children. Also, it was seen that a better design would dig into the ground to bring up more of the radiated soil. They did, however, have one unexpected feature - they were so good at concentrating heavy metals that a use decontaminating depleted gold mines was anticipated.