Space Memorabilia

Im a jeweler who wish to start a series of little space invaders pendants and I wanted to know if im legally allowed to sell these characters.

There are memories of many invaders space out there and many companies sell key chains t-shirts sand.

I do not know where to start? Is it a trademark, copyright, what????
Please help

The shape of the characters is part of the copyright in the game as a whole.

If the items are being sold as Space Invaders, it's probably a protected name and you may have to check with the copyright office
you can change the name slightly to be able to sell your products