Answer:
I have feet on my head
What has many teeth but can't bite?
I know a word of letters three. Add two and fewer there will be. What is the word?
So simple, that I can only point. Yet I guide men all over the world.
I am quick when Iām thin. I am slow when Iām fat. Wind is my worst nightmare.
Give it food and it will live, give it water and it will die.