The Mean Machine is designed with a round glass dome, four wheels, two mechanical hands, and a light bulb on top.
The Mean Machine is used to turn a person or puppy with a pure heart into an evil person or a vicious guard dog. Marvin McNasty used this machine in an attempt to rule the world. However, the effects of the Mean Machine can be reversed when one person says "I Love You" to the person who was affected by the Mean Machine. The Mean Machine can even turn the nastiest person alive into a good person when it reversed Marvin McNasty, Lumpy, and Bones' personalities.