Every time I visit a school, the kids dream up a far-fetched scenario for me to illustrate, and in the last 15 minutes of the session we pull it all together and create a picture. I'm making them all available here as downloadable, printable pages that can be used in the classroom. You can colour them in, add extra details and backgrounds, and write the story to go with the picture.
I'll be adding new pictures regularly, so check back often.