A Mythical Mystery Creature

I love to run through the fields of your imagination because I am a mythical creature. I gallop and frolic and eat make-believe grass. I am white. I am beautiful. My favorite animal in the real world is a horse because I resemble one. However, I have one extra special feature that real horses do not have. It is long and pointy! It comes out of my forehead. I will give you one more .....