Binky's evil twin is a character imagined by Buster in "Binky Rules" to explain the graffiti around the school. According to Buster, the evil twin plans to ruin Binky's reputation so he can take over his identity. In the book, Binky was disappointed to hear that the evil twin isn't real and actually missed him. He bears some resemblance to Brain's "Mr. Hyde" form from the Jekyll and Hyde song of "Arthur's Almost Live Not Real Music Festival".