Fanboy is based on "Mr. Fan", a cartoon character and imaginary friend from around the time that I was in first and second grade. Mr. Fan himself was based on an old Samson Safe-Flex electric fan. That character popped into my mind's eye when I first came across the term "fanboy" while reading a Clark Dissmeyer editorial in Clay Geerde's "Comix Wave" about fanboys acting badly at a comics con. Thus Mr. Fan got recycled into Fanboy.