Answer:
Drop me and the world will shatter. You can always find me where you empty your bladder. What am I?
I am expelled from you orally with a sound
Keep doing me to avoid lens dryness
You seek me out when your hunger's ripe. I sit on four legs and smoke a pipe.
I walk on 4 legs in the morning 2 legs at noon and 3 legs at night.
Give it food and it will live, give it water and it will die.