Jemmy is a character from the novel "The Prince and the Pauper" by Mark Twain. He is a young boy who serves as a guide and companion to the main character, Tom Canty, who dreams of becoming a prince. Jemmy is resourceful and street-smart, helping Tom navigate the challenges of life in the royal palace. In the story, Jemmy's loyalty and friendship play a crucial role as he supports Tom during their adventures. The novel explores themes of social class and identity, highlighting the stark differences between the lives of the rich and the poor in 16th-century England.