Classic Poem

First I saw the white bear,
Then I saw the black;
Then I saw the camel
With a hump upon his back;
Then I saw the grey wolf,
With mutton in his maw;
Then I saw a wombat
Waddle in the straw;
Then I saw the elephant
A-waving of his trunk;
Then I saw the monkeys--
Mercy, how unpleasantly they--