Everything you need to understand or teach The Nargun and the Stars by Patricia Wrightson.
The Nargun and the Stars is a touching story about a recently orphaned boy, Simon, and his quest for a place free from the depredation of mankind and its machinery. Simon's adventure involves conflict with the Nargun, a stone creature that is indestructible. It kills humans, sometimes for food, but mostly out of rage at the unnatural noise of their destructive machinery. The creature is therefore a threat to Simon's newfound home of Wongadilla, just as the humans threaten the peace the Nargun seeks. The humans win the conflict with the Nargun with the help of another mythical creature, the Potkoorok. This creature is a supernatural trickster who loves to play practical jokes. Its antics provide a playful and humorous subplot to balance the more serious major conflict of the story.
The ideas generated by the story call into question the right of humanity to destroy the environment...