I had an imaginary "bully" when I was young. As a coping mechanism or something. See, people didn't mock me because I was overweight, had a lisp, and because the teachers in a public school system were sociopaths, there was just a dark shadow figure that seethed whenever I succeeded.
Thus when I remembered to do my homework, got to go on playdates, and whatever, I was winning a victory over the seething shadow man. Whenever I was bullied, it was the fault of the seething shadow man.
Of course, when I played Lacrosse I fantasized about being possessed/guided by an ancient Native American Lacrosse player but that didn't make me play any better.
Anyways if imaginary friends of young American boys in the 90s truly worked like they did in Fosters the entire home should be packed up with Naked Azulas and other cartoon crushes.