What Is A Unicorn?

Truly, a unicorn is more a mirage- a Schrödinger's Cat phenomenon in and of itself. It is nothing and something, and empty and full, all at the same time.
Like a white mist, or a great web to get caught up in, if you should be so willing to be so unaware, and to sell yourself so readily.

What sort of creatures and what sorts of delusions and what sorts of circles shall you find yourself lost to, if you are so very taken by the illusions in the mist? And then taken by the mist?