[quote name='boatofcar']I'm not worried, and I'll tell you why. None of those characters' images are copyrighted. If I were doing team logos or something like that, I would be in clear violation of the law because those actual images are copyrighted, which is why when you see any kind of logo it has a (R) next to it. You'll notice on the page I never mention character names or any copyrighted names at all. This, I think, is enough to put me in the clear.
Of course, IANAL (yay slashdot), but I feel like I can do something like this in good conscience.[/QUOTE]
Not to scare you, and not to provide you actual legal advice (though I might recommend talking to a lawyer), but you are confusing trademark and copyright, and they are two completely different areas of the law. The "R" you mention indicates a registered trademark, which is generally used for logos and brand names. Trademarks are applied to these logos to protect brand identity and commercial viability of a companies name and identifying features.
Copyright is a separate branch of the law which protects creative content which has been fixed in a tangible medium. A registered copyright is shown by the marker "C" in a circle next to the image or work. However, copyright protection applies even if the work is not registered. The characters you are copying are copyrighted material, and it is likely that your work is infringing on the copyrights of these companies, as you are creating derivative works from their copyrighted characters. It does not make a difference that you did not use the character's names, the design of the characters are copyrighted material, you are still infringing, and might be subject to legal action. The most common defense you could assert, fair use, will likely not be valid, as you are attempting to make a profit from the infringing materials.
At this point, you probably simply are not on these companies' radars, but I would be VERY careful, and would recommend talking to a local lawyer very soon. Probably not the best place to say it, but your work is excellent. PM me if you have any questions, and I'll try to answer them as best as I can.