Which C.S. Lewis novel follows a boy named Eustace on the ship Dawn Treader?

The C.S. Lewis novel featuring Eustace aboard the ship Dawn Treader is The Voyage of the Dawn Treader.

Published in 1952, the book follows Edmund and Lucy Pevensie during a return visit to Narnia. They travel with their cousin Eustace Scrubb aboard the ship Dawn Treader, commanded by King Caspian. The voyage takes the characters through a series of islands and unknown waters as they search for seven lost lords of Narnia.

Eustace begins the story as a selfish, unpleasant boy. After being transformed into a dragon, he undergoes a moral change and eventually becomes a more generous and dependable person. His transformation is one of the novel’s best-known episodes.

The book is sometimes confused with The Silver Chair because both feature Eustace and a major quest. The Silver Chair, published in 1953, instead follows Eustace and Jill Pole in their search for the missing Prince Rilian. The Dawn Treader is specifically the ship and the 1952 voyage novel.