Kryptonians are the race of people from the planet Krypton. On the surface, they resemble Humans from Earth completely; however, they have evolved many complex physical differences. Superman, Supergirl, Krypto and General Zod are all examples of Kryptonians living on Earth.
While living on Krypton, or any planet under a red star, Kryptonians seem relatively just as physically powerful as normal humans, but have highly advanced technology which allows them to control their world. However, on Earth, which has both lesser gravity and a yellow star, Kryptonians gain superpowers. It should be noted, however, that in the Golden Age Comics, Kryptonians were depicted as having evolved to have superpowers on their own planet, but these powers were heightened by living on Earth's reduced gravity. Originally, before Superman gained so many other powers, he was presented as having the same super strength, speed and invulnerability as all Kryptonians, even on their homeplanet Krypton. Starting on January 16, 1939, Siegel and Shuster's original stories appeared in a daily newspaper comic strip. The first days of the Superman daily newspaper strip retold the origin in greater detail, focusing on his departure from Krypton. It is revealed that Kryptonians had evolved to the ultimate peak of human perfection. There are images showing Kryptonian jumping through air as Superman does on Earth and it can assumed by early depictions of Superman's parents all have his powers of super leaping on Krypton. In this retelling, the planet Krypton and Superman's biological parents, Jor-L and Lara, are called by name for the first time.Siegel and Shuster have themselves discussed a number of influences that impacted upon the character. Both were avid readers, and their mutual love of science fiction helped to drive their friendship. Siegel cited John Carter stories as an influence: "Carter was able to leap great distances because the planet Mars was smaller that the planet Earth; and he had great strength. I visualized the planet Krypton as a huge planet, much larger than Earth"
Since the destruction of Krypton, Kryptonians have become nearly extinct. It was originally believed that Superman was the sole survivor of Krypton, but since then many additional kryptonians have appeared.
Powers and abilities
See: Kryptonian Powers
Examples of Kryptonians