I've seen numerous design portfolios online that involve characters from movies, TV, games, you name it.
I'm building a portfolio and for one project I was thinking of creating a few mobile UI screens of a Star Wars "character database" app that would show an image of a few characters and possibly a brief description of each. I never intend to build the app, just a simple design.
As of late Dribbble has been full of fan art, UIs, animations, etc. involving Star Wars. I'd imagine it would be okay as long as there's no profit from the work/design, but just wanted to check in and see what most people would say.