Mike Believe (a pun on the phrase make believe) was the new student at Pokey Oaks in "Imaginary Fiend".
Mike Believe is voiced by Aaron Spann, who was 10 years old when it aired, making him the youngest guest star or actor to do a voice-over on The Powerpuff Girls.
He seemed to be new in town, as the class didn't seem to know him and Ms. Keane introduced him to the class at the beginning of the episode. He really wants a friend, so he creates Patches, an evil ratty-wizard-type person, who causes trouble for the whole class. Blossom finally figures out (after the girls try and fail at fighting him) that they have to create an imaginary friend to get Patches out of there. The girls create a bunny, who wears a pretty dress and combat boots and who has powers similar to the girls, along with a sweet, motherly voice. The Bunny fights Patches and sends him on his way. Bubbles tells Mike (after he explains that all he wanted was a friend) that the girls will be his friends.
Season 1:Monkey See, Doggie Do • Mommy Fearest • Insect Inside • Powerpuff Bluff • Octi Evil • Geshundfight • Buttercrush • Fuzzy Logic • Boogie Frights • Abracadaver • Telephonies • Tough Love • Major Competition • Mr. Mojo's Rising • Paste Makes Waste • Ice Sore • Bubblevicious • The Bare Facts • Cat Man Do • Impeach Fuzz • Just Another Manic Mojo • Mime for a Change • The Rowdyruff Boys • Uh Oh Dynamo Season 2:Stuck Up, Up and Away • Schoolhouse Rocked • Collect Her • Supper Villain • Birthday Bash • Too Pooped to Puff • Beat Your Greens • Down n' Dirty • Dream Scheme • You Snooze You Lose • Slave the Day • Los Dos Mojos • A Very Special Blossom • Daylight Savings • Mo Job • Pet Feud • Imaginary Fiend • Cootie Gras • The Powerpuff Girls Best Rainy Day Adventure Ever • Just Desserts • Twisted Sister • Cover Up • Speed Demon • Mojo Jonesin • Something's a Ms. • Slumbering with the Enemy Season 3:Fallen Arches • The Mane Event • Town and Out • Child Fearing • Criss Cross Crisis • Bubblevision • Bought and Scold • Gettin' Twiggy With It • Cop Out • Three Girls and a Monster • Monkey See, Doggy Two • Jewel of the Aisle • Super Zeroes • Candy Is Dandy • Catastrophe • Hot Air Buffoon • Ploys R' Us • The Headsucker's Moxy • Equal Fights • Powerprof. • Moral Decay • Meet the Beat Alls • Helter Shelter • Power Lunch Season 4:Film Flam • All Chalked Up • Get Back Jojo • Him Diddle Riddle • Super Friends • Members Only • Nano of the North • Stray Bullet • Forced Kin • Knock It Off Season 5:Keen on Keane • Not So Awesome Blossom • Power-Noia • Monstra-City • Shut the Pup Up • Toast of the Town • Divide and Conquer • Burglar Alarmed • Shotgun Wedding • Save Mojo • Substitute Creature • The Boys Are Back in Town • See Me, Feel Me, Gnomey • Pee Pee G's • Boy Toys • Seed No Evil • The City of Clipsville • Lying Around the House • Bubble Boy • A Documentary • Girls Gone Mild • Curses • Bang for Your Buck • Silent Treatment • Sweet 'n' Sour Season 6:Prime Mates • Coupe D'Etat • Makes Zen to Me • Say Uncle • Reeking Havoc • Live & Let Dynamo • Mo' Linguish • Oops, I Did It Again • A Made Up Story • Little Miss Interprets • Night Mayor • Custody Battle • The City of Nutsville • Aspirations • That's Not My Baby • Simian Says • Sun Scream • The City of Frownsville • West in Pieces • Crazy Mixed Up Puffs • Mizzen in Action • Roughing It Up • What's the Big Idea? • Nuthin' Special • Neighbor Hood • I See a Funny Cartoon in Your Future • Octi-Gone Reboot: