What Am I Riddles

Question: Without me, nothing exists. What am I?

Question: I have four feet in total, two that I stand on and two that I don't . What am I?

Question: Black were are and much admired, Men seek for us if they are tired We tire the horse but comfort man, Tell me this riddle if you can.

Question: I can easily impale meat, And also can withstand the heat of a charcoal burning fire.

Question: This old one runs forever, but never moves at all. He has no lungs, nor a throat, But you can hear his mighty roaring call.