Answer:
Iron on a mammal. Mammal on your feet.
who do you think you know but sometimes you don't
Always wax, yet always wane: I melt, succumbed to the flame. Lighting darkness, with fate unblest, I soon devolve to shapeless mess.
What is it that was given to you, belongs only to you. And yet your friends use it more than you do?
It cannot be seen, it weighs nothing, but when put into a barrel, it makes it lighter.
If a rooster lays an egg on the exact peak of a barn, which side does it fall?