What does mean being chased by a skull in a dream?

It sounds to me like you might have some stressful people or situations in your life... as if these beasts are people or situations that you feel are impacting your well being. Try thinking about if you are having issues with someone or something that is bothering you. Making some progress to solve the problem might make you sleep a little easier. I get dreams like this all the time (I had one where Abraham Lincoln was driving an old VW Beetle and trying to kill me, lol!) but it usually boils down to something that is bothering me in my everyday life. Good luck!!