Batman
The first Batman story, "The Case of the Chemical Syndicate", was published in "Detective Comics" #27 (May 1939). Finger said, "Batman was originally written in the style of the pulps", and this influence was evident with Batman showing little remorse over killing or maiming criminals. Batman proved a hit character, and he received his own solo title in 1940 while continuing to star in "Detective Comics". By that time, Detective Comics was the top-selling and most influential publisher in the industry; Batman and the company's other major hero, Superman, were the cornerstones of the company's success. The two characters were featured side-by-side as the stars of "World's Finest Comics", which was originally titled "World's Best Comics" when it debuted in fall 1940. Creators including Jerry Robinson and Dick Sprang also worked on the strips during this period.
Batman of Zur-En-Arrh
Batman of Zur-En-Arrh first appeared in "Batman" #113 (February 1958), in a story titled "Batman—The Superman of Planet-X!". It was written by France Herron and drawn by Dick Sprang. In the story, Tlano, the Batman from Zur-En-Arrh, brings Earth's Batman to his planet to help him battle giant robots piloted by an unidentified alien race. While on the planet, Earth's Batman discovers he has "Superman-like" powers through similar means of the Superman of his world. The end of the story leaves it ambiguous to the reader whether Batman's adventure was real or a dream.