Answer:
Sleeping during the day, I hide away. Watchful through the night, I open at dawn's light. But only for the briefest time, do I shine. And then I hide away. And sleep through the day.
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 leathery snake, with a stinging bite. I'll stay coiled up, unless I must fight.
In many years, not much has happened. In many minutes, a lot has happened. In one second, everything has happened.
Who is he that runs without a leg. And his house on his back?
What sphinxes employ and players enjoy.