Any person or character who displays quixotism.
A famous 1605–1615 Spanish novel by Miguel de Cervantes (1547–1616), whose full title is El ingenioso hidalgo don Quijote de la Mancha (The Ingenious Gentleman Don Quixote of La Mancha).
The protagonist of this novel.
One who creates fantasies.
One living in a fantasy world.
A writer who writes in the fantasy style.