Dreams involving unusual animals, such as a horse, often symbolize power, freedom, and energy. The enormous size of the horse may represent a significant force or influence in your life that you feel either excited or overwhelmed by. The yellow light could symbolize enlightenment, clarity, or optimism, suggesting that you are gaining insight or a new perspective on a situation.

The lightning trail left by the horse could indicate that this influence is quick and impactful, leaving a lasting impression on your life. It might suggest rapid changes or sudden realizations that are transforming your environment.

Overall, this dream may be reflecting a powerful transformation or an awakening in your life, encouraging you to embrace the energy and potential that comes with it. Consider what areas of your life are currently undergoing change and how you might harness that energy.