Answer:
When one does not know what it is, then it is somethingอพ but when one knows what it is, then it is nothing.
I travel with deer all over the world and make the night special for all boys and girls. I happily drink milk and eat your cookies and then I give you all sorts of goodies. Who am I?
What can you blow up and keep intact?
I usually wear a yellow coat. I usually have a dark head. I make marks wherever I go.
What can an elephant and a shrimp both be?
When is it bad luck to see a black cat?