Answer:
I cannot be burned in fire or drowned in water
I am always hungry, I must always be fed. The finger I lick will soon turn red. What am I?
My teeth are sharp my back is straight to cut things up it is my fate.
I am a key that is playful. What am I?
I shrink smaller every time I take a bath.
Whoever made me don't want me. Whoever bought me don't need me. Whoever use me don't know me.