After joining the Fremen, Paul Atreides chooses the name Muad'Dib for himself. It is the Fremen name for a small desert mouse on Arrakis, an animal admired for surviving and finding its way through the harsh desert.
Paul also receives the secret Fremen sietch name Usul, meaning the base of a pillar. Usul is used within his tribe, while Muad'Dib becomes his public name and war identity. This distinction is why both names appear in Frank Herbert’s Dune, but Muad'Dib is the answer to the question about the name Paul chooses for himself.
The choice has symbolic weight. The desert mouse avoids the sun, creates or conserves water, and thrives in conditions that defeat larger creatures. Stilgar explains that these qualities make Muad'Dib a powerful foundation for Paul’s life among the Fremen. Later, Muad'Dib becomes more than a personal name: it is tied to Paul’s political leadership, religious image, and imperial title.