Katie is a playful girl with brown hair and vivid green eyes. She lives in a paradise where kids eat candy for meals and watch cartoons all day. She and Numbuh 1 have a great time in Operation: U.T.O.P.I.A., but when he finds the loophole in Chester's world, the fun stops cold. Katie turns vicious and attacks him, but then Nigel activates his J.E.T.A.B.O.O.T.S. and flies away from Katie and her illusions.