Answer:
I cost no money to use, or conscious effort to take part of. And as far as you can see, there is nothing to me. But without me, you are dead.
I can sizzle like bacon, I am made with an egg. I have plenty of backbone, but lack a good leg. I peel layers like onions, but still remain whole. I can be long, like a flagpole, yet fit in a hole.
Runs over fields and woods all day. Under the bed at night sits not alone, With long tongue hanging out, Resting at your feet until we go for a walk
What can you share and still have all for yourself?
What has a bell but isn't a church. Is full of air but is not a balloon?
Those with eyes bigger than their stomach will definitely leave the restaurant with one of them. It is named after a house pet as well.