Answer:
First I may be your servant's name; then your desires I may proclaim; And when your mortal life is over hold all your wealth within my power.
Though not a plant I have leaves. though not a beast I have spine. Though many wouldn't need me I am more valuable than wine.
Crooked as a rainbow and slick as a plate, ten thousand horses can't pull me straight. What am I?
I start in little but I end in full you'll find me in half and complete.
I make a loud noise when changing jacket. I become bigger and delicious.
It has no top or bottom, but it can hold flesh, bones, and blood all at the same time.