Superman succeeded in establishing a vast, detailed world with a rich history that surrounds aliens and metahumans. It even introduced several iconic comic book characters with roots far beyond Superman’s, including the Green Lantern, Hawkgirl, Mr. Terrific, Metamorpho, and the Engineer. This was all done on planet Earth.

James Gunn, the head of DC Studios and director of "Superman," revealed the first look at the new "Supergirl" movie — with a warning.