Answer:
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.
A skin have I, more eyes than one. I can be very nice when I am done.
I turn around once. What is out will not get in. I turn around again. What is in will not get out.
It flies when it's on and floats coming off.
Pirates put their booty in it.
I have feet on my head
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?