Here's an illustration I finished at the end of last year for a children's theatre company. They do this fantastic project with kindergarten-aged children where they go into the class and help them develop short stories about whatever they like. (The compilation I read was peppered with ninja references). The kids write the stories, draw pictures to accompany, and then act them out for the whole class. The theatre company then assembles all of their stories and pictures into a booklet for the classroom and this will be its cover!
(My friends and I used to do this in grade 4. So what if we were really too old by that point and the storylines I'm sure made no sense, but, whatever, the teacher got a 20 minute break, and no one ever gave us a book at the end of it.)