I invented animals and birds ...

I invented animals and birds - I had about two dozen. After working on them for six months, I sat down and just for fun wrote two dozen poems to accompany the drawings. It was for no one to every see, but a friend sent me in to an editor.
 Jack Prelutsky

Quotes from the same author

I accept challenges, I have always done that in writing.
 Jack Prelutsky
After I'd produced about two dozen pen and ink drawings, one evening I decided that they needed poems to accompany them. I still have no idea where that notion came from, but it took me about two hours to produce verses for these creatures.
 Jack Prelutsky