Parody is defined as "contemporary usage, is a work created to mock, comment on, or make fun at an original work, its subject, author, style, or some other target, by means of humorous, satiric or ironic imitation." Parody happens across all forms of entertainment but surely by using an idea that wasn't originally under ownership of the new creative theres got to be some legal fluff surrounding it.
In the United States of America, parody is considered work derived from a previous source but claims for owners can be dismissed under the Fair Use doctrine which allows limited use of copyrighted material without authorisation from the rights holder under the basis that the parody fell under the the proper definition.
If I was to create a comic where in a teenager is bitten by a radioactive ant to become a super hero and show him struggling with being a teenager and a super hero, this would not be under the definition of Parody as I've taken elements from one preoperty and just switch a few details, essentially ripping off a previous idea. If I was to create a comic in where a Spider was bitten by a radioactive shy, bookish human thus gaining the proportionate abilities of a teenage nerd and then chronicle it's experience as it deal with these terrible new powers, this would fall under the definition of Parody as it it's clearly taking some elements of the original and changing the perspective around, adding comedic and even more fantastical elements to which it has become something else that draws it's origins from a different piece of work.
In the UK the use of Parody is much harder to acquire. Citing that one must recieve permission from the original copyright holder before the Parody is performed, although there are exceptions such as;
- Part of the underlying work is not 'substantial'.
- The use of the underlying work falls within the fair dealing exception for "criticism, review and news reporting".
- Enforcement of copyright is contrary to the public interest.
It seems that when it comes to parody there are very fine line between what the law deems as okay and whats not okay, with the most complicated part being the definition of the amount of worked used and if you have contributed anything new to it to make it different from the original. The best example of mainstream Parody would most likely be the Scary Movie series of films which has built up a franchise of parodying various horror movies for the sake of make a new comedy movie from those pastiches. If you ever find your work being copied always hold your fire to make sure that it's not a parody so that you don't waste money chasing the wrong guys.