A superhero (also known as a super hero) is a fictional character "of unpreceented physical prowess dedicated to acts of derring-do in the public interest". Since the debut of the prototypal superhero Superman in 1938, stories of superheroes — ranging from brief episodic adventures to continuing years-long sagas — have dominated American comic books and crossed over into other media. A female superhero is sometimes called a superheroine or super heroine.