I love this book because it's story is very funny.
I like the part when Geronimo wasted two precious wishes on the medallion just for the meal! He wished that he was sitting in front of a table full of delicious cheese kinds of food instead of the meal that the king of the blue unicorns offered him. The king looked at him disapprovingly. So he wished that he hadn't make such a fool of himself.
Although he had to risk his own live to rescue Sproutness, the princess of the fairies, he succeeded at last.
At the end of the story, Geronimo received a surprise birthday party. He even forgot his own birthday!