Four robots were built in total, one of which was an early, dim-witted prototype, and three that were stronger and faster (but looked identical). They were each equipped with Chill-guns that could instantly freeze a living creature into an ice statue. When Sonic the Hedgehog defeated the Chiller, he destroyed three of the robots. When the Chiller decided to give up being a villain (since he wasn't really very good at it anyway), the fourth robot was re-branded as a "mop bot" and used to help clear up all the melted ice from the Pleasant Zone streets.