Fake Mustache by Tom Angleberger

Regular kid Lenny Flem Jr. is the only one standing between his evil-genius best friend—Casper, a master of disguise and hypnosis—and world domination. It all begins when Casper spends money from his granny on a spectacularly convincing fake mustache, the Heidelberg Handlebar #7. With it he’s able rob banks, amass a vast fortune, and run for president. Is Lenny the only one who can see through his disguise? And will he be able to stop Casper from taking over the world?

This will be yet another certifiable hit with the 9-12 year old set for Angleberger. This is completely absurd and silly story and they will love it!.