Here you go...
THE UNICORN SONG
Shel Silverstein
A long time ago when the Earth was green
There was more kinds of animals than you'd ever seen
They'd run around free while the world was being born
And the lovliest of all was the unicorn
Chorus: There were green alligators and long necked geese
Some humpty back camels and chimpanzees
Cats and rats and elephants, but sure as you're born
The loveliest of all was the unicorn
But the lord seen some sinnin' and it caused him pain
So he said "Stand back - I'm gonna make it rain!
So hey brother Noah, I'll tell you what to do.
Build me a floating zoo."
Now Noah was there and he answered the callin'
And he finished up the ark just as the rain started fallin'
And he marched in the animals two by two
And he sang out as they went through
Well Noah looked out through the driving rain
But the unicorns were hiding; playing silly games
They were kickin' and a-splashin' while the rain was pourin'
Oh them foolish unicorns.
And then the ark started moving and it drifted with the tide
And the unicorns looked up from the rocks and they cried
And the water came up and sort of floated them away
That's why you've never seen a unicorn to this day.