You could do a Harry Potter Encyclopedia.
Even if you screw it all up 'cause you ain't even seen all of them Harry Potter movies let alone read any of them books, heck, it'd prolly be better for you in the long run, if the encyclopedia was totally screwed up and wrong in a million places, 'cause it'd create a "furor of controversy" among the Harry Potter fans and stuff.
"Frogbeard is not the name of the guy in charge of the Frogwarts!"
And then that chick that writes those books would prolly sue you to protect her intellectual property.
And that'd make you famous.
And then you could use the media attention to do something useful.
Heck, if your encyclopedia was totally wrong about Harry Potter in every way, you could just change the title, y'know, after saying there was some sort of mistake at the printers or something.
And then the Hairy Walter Encyclopedia (or whatever) would be your intellectual property, and you could use the whole Harry Potter Hubbub to have your encyclopedia turned in a series of motion pictures and stupid books and stuff.
See, that's like taking lemons and converting 'em into gold, right there.
I'm surprised more people haven't done that already ahaha.