This one might be a little tricky, but I think it can be a lot of fun too. Take a fairytale, or something akin to a fairytale - it can be a folktale or a legend if you like - and merge the main character with one of FLB's creation. As an example, Echo could be H.C. Andersen's Little Mermaid, with the appropriate alterations to the story. Then write 100 words about how the fairytale would be with this new hero or heroine.
Remember to specify which fairytales and fairytale characters you use, as well as which FLB books and characters. Do ask if you have any questions, and enjoy. ♥