Jo Files is one of the eighteen men who live in the kingdom of Oogaboo.
Jo Files is a young fellow, both intelligent and ambitious.
He has twelve trees which bear steel files of various sorts. He also has nine book-trees, on which grow a choice selection of story-books. Files is generous with his books, but the people of Oogaboo care little for books so he reads most of them himself.
Queen Ann recruited him to serve in her army, and he insisted on being the sole private. Since the rest of the soldiers were officers, Files was eager to fight the enemy and become a hero. He armed himself with the ripest and biggest musket on the kingdom's gun-tree.
The army unexpectedly found itself in a deserted country, and while the sixteen officers began to complain Private Files enjoyed the hardships they suffered. When they encountered a Rak, Files bravely stood his ground, shooting the monster three times while his officers ran away.
They later encountered a party consisting of the Shaggy Man, Tik-Tok, Betsy Bobbin, Hank the Mule, Polychrome, and Ozga the Rose Princess. Files was commanded to take them prisoner and bind them, but since three of the party were girls he refused and resigned his position. Tik-Tok took his place as private, and Jo Files struck up a very friendly relationship with Ozga. (Tik-Tok of Oz)