Kryptonian

Kryptonians are a fictional extraterrestrial race within the DC Comics universe that originated on the planet Krypton. The term originated from the stories of DC Comics superhero, Superman. The stories also use "Kryptonian" as an adjective to refer to anything created by or associated with the planet itself or the cultures that existed on it. Kryptonians are indistinguishable from humans in terms of their appearance, but in terms of their physiology and genetics they are vastly different. In some continuities, Kryptonians are difficult to clone because their DNA is so complex that human science is not advanced enough to decipher it. The cellular structure of Kryptonians allows for solar energy to be absorbed at extremely high levels. On the planet Krypton, which orbited a red star, their natural abilities were the same as humans. When exposed to a young yellow star like Earth's Sun, which is smaller than their own sun and has a vastly higher energy output, their bodies are able to absorb and process so much energy that it manifests as vast superhuman powers (such as superhuman strength, superhuman speed, invulnerability, flight, x-ray vision, heat vision and superhuman senses). Almost all Kryptonians were killed when the planet exploded shortly after the infant Kal-El was sent to Earth. In some continuities, he is the planet's only survivor. In other canons, there is a last daughter of Krypton Kara Zor-El, cousin of Superman and known as Supergirl. Krypto was the family dog in Jor-El's home and was used for a test flight of the rocket that ultimately brought baby Kal-El to Earth. These three were the surviving Kryptonians, who became Earth's greatest heroes.