The main character of The Phantom Tollbooth is Milo. As the story begins, he is not interested in anything at all, and consequently, he is not very interesting himself. King Azaz, for example, mutters, "What an ordinary little boy," when Milo admits that he cannot sing, or tell stories, or do anything to entertain.

However, as Milo continues to experience surprises, the reader can see that he is actually intelligent and perceptive. He has simply been unwilling to apply himself. By the close of the book, Milo has completed the quest set for him, and all of his good qualities have been revealed: intelligence, determination, honesty, resourcefulness, and love.

Through his experience in the Kingdom of Wisdom, Milo becomes a complete— and much more interesting—person.

The two characters that accompany Milo through most of his trip are the ticking watchdog, Tock, and the...