Not sure about the Walt Kelly/Pogo reference, but a variation of that came in Mad Magazine in the early 60's. Also not sure about the exactness of the first verse, but the second verse I'm certain is accurate:

Sing a song of nonsense, pocket full of pie
4 and 20 blackbirds, backed until they cry
When the stove was opened, the birds began to swing
Wasn't that a swingin' dish to set before the king?

The King was in his counting house, counterfeiting money
The Queen was in the parlor, looking at the funnies
The maid was in the garden, hanging by her toes
Along came the North Wind, and that's the way she froze.