Here are two wonderful pieces of nonsense this one by Christopher Isherwood

The common cormorant or shag
Lays eggs inside a paper bag
The reason you will see no doubt
It is to keep the lightning out
But what these unobservant birds
Have never noticed is that herds
Of wandering bears may come with buns
And steal the bags to hold the crumbs.

And another one by that great poet Anonymous

What a wonderful bird the frog are!
When he stand he sit almost;
When he hop he fly almost.
He ain’t got no sense hardly;
He ain’t got no tail hardly either.
When he sit, he sit on what he ain’t got almost.