The Ice Key is hidden inside another game pak. You will have to learn the Grip Grab move to get it. Go to Jinjo Village, go behind the Green Jinjo's House, and find the sandy spot. You will see a crack in the wall. Go up on the platform near there to reach it and climb your way across to a hole. Be careful, because there are plants that will bite you. When you reach the cave, you will see the Game Pak.