Thankfully, nature has seen fit to provide its own warning markings on this mutated black widow: three green triangles that meet at a point.
These radioactive spiders hunt throughout the ruins of Ancient cities. Their webs glow with sickly green radiation, and they use smaller strands to draw their prey to their doom. Their venom is both poisonous and radioactive.
Gamma World stats: Change the monster’s type from “natural beast” to “terrestrial beast” and ignore the Alignment/Languages line.