Answer:
It is something you make after you've weighed your options.
Casper was a friendly one and Demi Moore made a clay pot with one.
Gumby and yoga instructors have this in common.
Mouth up it gets filled, mouth down it gets empty.
If you are to keep it, you must first give it to me. What is it?
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.