Wheel robots appear as a metal circle. The circle appears as two U-shaped pieces of metal, with each top side connecting, and in the middle of where they connect there is a glass eye. Below that is a pink mouth. Blades are placed on the outsides of the wheel.
Wheel robots have roll back and forth, with no attack. They move slower than most enemies, and will not roll off ledges. However, if Toxic comes in contact with a wheel robot, he will lose one fourth of his health. In order to avoid them, they can be destroyed by the explosion of any bomb that comes in contact with them.
In one level of Toxic, if the platform underneath the wheel robot is destroyed, the wheel robot will roll down to the ground as if going down a slope or even continue rolling, but upwards and sometimes falling.