if you use graphics from others you have the copyrights issue...you can't just take any thing from internet and use it for your map...If you want something you have to make it yourself starting from scratch...
You can make a thing that is under copyright protection but you have to make it yourself and change some minor things...but you will always change some things if you make it yourself, it will never be exactly the same.
So if you want to use a famous fiction thing, use your designer skill to make it yourself
