I learned it the following way:

Be kind to your webfooted friends
For that duck may be somebody's mother
Be kind to your friends in the swamp
Where the weather is always damp!
You may think that this is the end
And it is, but to prove that we're all liars
We'll sing it again and again
And each time a little bit higher!

That "we're all liars" bit is the part that makes me crack up whenever I hear it playing in the background on patriotic holidays.