Grampa in Oz (1924) is the eighteenth of the Oz books created by L. Frank Baum, and the fourth written by Ruth Plumly Thompson.
Things are going from bad to worse in the dilapidated kingdom of Ragbad; even the rag crop is failing. To top it all off (or not), King Fumbo's head is blown away in a ferocious storm (with "ten thousand pounds of thunder"). Prince Tatters of Ragbag, and Grampa, a former soldier and the bravest man in the kingdom (population 27), set out to search for King Fumbo's lost head, and a fortune to save the kingdom, and a princess to boot. They are joined by Bill, an iron weathercock from Chicago, who was brought to life by an electrical storm and blown to Oz.