Water

Water can take many forms.  It can rise up to the heavens and become rain and dew, and it can fall to the earth and become rivers and streams.  Human bodies are 98% water, and when water takes the form of our bodies, it also becomes our brain, and when it becomes our brain, water becomes all our thoughts, our memories, our personalities, our hopes, our fears, and our dreams.  It becomes all of culture and civilization, it becomes art and leisure, it becomes fiction, it becomes The Slender Man, and it becomes our perceptions, and at that point, the whole universe, at least as we know it, is all water.

Water also takes the form of myriad other beings, both real and imagined.  Pic related.