Parody is protected. Nobody ever heard of Mad magazine for chrissakes? Just don't use the actual names of the characters or the book/movies. Though that last bit isn't such a big deal usually if it's not for profit. Most companies have better things to do than squash fan art. There are exceptions though... In the past Fox, shut down some PC game mods based on... I believe... Aliens, Funimation Made some guys doing a Dragonball Z mod shut down (Only cuz it was better than their own game :p) Also stay away from Disney... they will try to sue anyone!