Two of the Circuit rats coming from Amanda’s lab have taken their own names, becoming Cookie and Jelly Bean - their favorite foods. Cookie is rat number 836 and Jelly Bean is 832, and both rats have their number marked above their rump. Their full version numbers are MP4-68P-836 and MP4-68P-832, respectively.

Cookie is distinguishable by white back-legs and a serious personality, while Jelly Bean has a white nose and tries to see the joy in a situation. Cookie tends to be a bit chubbier than Jelly Bean as well.

Cookie is female and Jelly Bean is male. Their hosts were bred in the lab for experiments, making them siblings.