This one is difficult. It is not original, and it is very, very old.
On Earth this warrior is strangely born
Of two dumb creatures, drawn gleaming
Into the world, bright and useful to men.
It is tended, kept, covered by women--
Strong and savage, it serves well,
A gentle slave to firm masters
Who mind its measure and feed it fairly
With a careful hand.
To these it brings warm blessings;
to those who let it run Wild
It brings a grim reward.
Good luck!
This
article, by the way, is very interesting and useful.