Radioactive cows are genetically altered cows created by German scientists. They explode if thrown, and they do heavy damage. They are a very powerful enemy and can take a bulk of Crypto's life. It can also destroy a tesla coil. They first appear in Rockwell, where Crypto must kill the scientists who made them, not the cows themselves. Then, they appear in Area 42, where Crypto, if he chooses, can use them as a weapon against the humans. They are never seen after that.
- If you can their minds, they say "brains...err..mooo.."
- They are fed radioactive hay which also explodes if thrown.