In the Midwest, mutant cockroaches are a common sight in the Wasteland. As in the Capital Wasteland, they can be encountered nearly everywhere, from old buildings to plains. However, they are drastically different and more dangerous than those met in the Capital Wasteland. They have a big, protected main body and small legs, and their saliva is incredibly toxic. They are very aggressive and attack every human unlucky enough to encounter them.
The Midwestern giant cockroaches are more varied than their Capital Wasteland cousins. Their size can also vary - they can be as small as their relatives in the Capital Wasteland or as big as an adult human.
Roachor is a unique giant cockroach encountered by the Warrior of the Brotherhood of Steel. It is an "advanced" version of a large cockroach, which lived in the Peoria facility. It appears Roachor was affected by the high amount of radiation coming from a strange production device that was used in manufacturing fusion batteries. He is bigger than any large radroach, the same size as a car, and his body glows with greenish radioactivity. His poison is deadlier than that of Midwestern radroaches.