Create 10 different scenes with few characters for a childrens book

I am trying write a children book with 10 different Scenes. Picture will include at least 3 characters (Ninja, Unicorn and a Monster) in various scenes. Forexample. Ninja Flying on Unicorn, Ninja fighting the monster etc etc.

All pictures/ Scenes/ Characters have to be copyright-able (fully unique and original). Also please show your previous work that you have done in creating new characters from scratch for a book.