And it has more whimsy and nonsense than any of the Oz books. Living jigsaw puzzles or people who carry their brains around in cans pale before how silly Mo is. Everything, from clothes to baked goods, grows from trees in Mo so no one has to work. No one ever dies in Mo. Getting chopped up or flattened is just an inconvenience.
Unlike most of Baum's fantasies, the Magical Monarch of Mo is a collection of short stories, connected by either about the monarch himself or one of his innumerable relatives. There is also a loose arc about the purple dragon, the greatest foe of the Monarch because the dragon is a candy hog. Oh, and likes to bite off people heads.
I found the Magical Monarch of Mo to be surprisingly fun. Not only is it lighter than almost anything else he wrote, it embraces the silliness without restraint, like how the monarch escapes from a pit by turning it upside down so he's on top. Not having an outsider like Dorothy actually helps because it lets the natives of Moe just romp about.
Many of the ideas in the book reappear in later books, like the idea of food growing on trees or no one ever dying in Oz. However, they get scaled back from the craziness that you find in Mo.
While the Monarch does not reappear in later books, moon is referred to in both the Oz books and the Life and Times of Santa Claus (Santa gets his candy from Mo).
The Magical Monarch of Mo is not one of Baum's greatest books. It definitely lacks dramatic tension when someone can get their head bitten off and be just fine. It also lacks a strong central protagonist like Dorothy for the readers to relate to and cheer on. However, it is still silly fun and if a child can handle someone getting squished flat and pumped back up, they will enjoy it.