The Magic of Oz by L. Frank Baum

Kiki Aru didn't know much about Oz and didn't know much about the beasts who lived there, but the old Nome's plan seemed to him to be quite reasonable. He had a faint suspicion that Ruggedo meant to get the best of him in some way, and he resolved to keep a close watch on his fellow-conspirator. As long as he kept to himself the secret word of the transformations, Ruggedo would not dare to harm him, and he promised himself that as soon as they had conquered Oz, he would transform the old Nome into a marble statue and keep him in that form forever.

Ruggedo, on his part, decided that he could, by careful watching and listening, surprise the boy's secret, and when he had learned the magic word he would transform Kiki Aru into a bundle of faggots and burn him up and so be rid of him.