Answer:
What can be heard and caught but never seen?
What instrument can make any sound and be heart, but not touched or seen?
A muttered rumble was heard from the pen, and I, in my walking stopped to look in. What was this I saw? A massive beast, hoofed, and jawed. With spikes upon its mighty brow, I watched as he struck the turf and prowled. And yet for all of his magnificence, he couldn't get out of that wooden fence.
Lovely and round, I shine with pale light, grown in the darkness, a lady's delight.
I can ruin your day, or darken your life. And while I'm expected, I'm never alright. I'm bad for business, and worse for your hair. Wherever I am, there's something not there.
What do you purposefully put lots of in and on your body, but run away from when you encounter it outside?