This dream may symbolize your fear of the unknown and your sister’s role represents your inner strength and courage to face it. The tap on the window could represent a call to action or a warning from your subconscious. The dead body in the driveway could represent a part of yourself or a situation that you have been avoiding or suppressing. Your sister’s initial disbelief and your own hesitation to believe her could suggest your reluctance to confront this issue. However, when you both see the dead body, it could symbolize your realization and acceptance of this aspect of yourself or situation. Your sister’s gun could represent your ability to protect yourself and take control of the situation. Shooting the zombie could symbolize your determination to overcome this fear. The zombie chasing you could represent your fear still lingering, but ultimately, you are able to escape it. This dream may be urging you to face your fears and take control of your life.