Answer:
Part carbon part water I am poison to the fishes. Many falsely claim my name I am the pause that refreshes.
You can catch me but cannot throw me.
I walk on 4 legs in the morning 2 legs at noon and 3 legs at night.
Santa shakes his belly like a bowl full of me
I go in dry and come out wet. The longer I stay in the stronger my surroundings get.
All about, but cannot be seen, Can be captured, cannot be held, No throat, but can be heard. Who am I?