Answer:
What flies without wings? What passes all things? What mends all sorrow? What brings the morrow?
What can you share and still have all for yourself?
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.
Stealthy as a shadow in the dead of night, cunning but affectionate if given a bite. Never owned but often loved. At my sport considered cruel, but that's because you never know me at all.
It is the assumed nocturnal symbol of Mr. Wayne. What is it?
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.