To see the grim reaper in your dream, signifies the negative, rejected aspects of your personality. It represents aspects of yourself that you have repressed. Alternatively, it symbolizes death or the end of something.
The grim reaper (figure of death) can represent:
Fear of death, or awareness of your mortality at the moment
Something or someone in real life trying to take something from you (time, attention, energy, focus, or anything physical, emotional, or mental) that you're not prepared to give
An ending or a change in something—such as a phase, project, or relationship
You feeling a sense of doom or a fear of impending failure