Answer:
They are toothy nocturnal immortals.
What kind of nail can be grown?
What falls down but never breaks?
It flows out of the soil, It burns you if it boils, And holds us in its coils, More valuable than gold, As black as it is old.
What can you hold in your left hand but can never hold in your right hand?
I touch the Earth, I touch the sky, but if I touch you, you’ll likely die. What am I?