Gianni Rodari's celebratory contest

This is one of the illustration I'm working on for a celebratory contest promoted by Bologna Children's Book Fair about the work of Gianni Rodari who was the most important writer of Italian children's literature. I'll soon post the coloured version.
If you are interested to the competition here's the link: http://www.bolognachildrensbookfair.com/bcbf09_internal1.asp?m=107&l=2&a=&ma=366&c=4114&p=1072009