Kryptonian

The Kyptonians are a sapient humanoid race that hails from the now destroyed planet Krypton, which was in orbit around a small red dwarf star named Rao. The Kryptonians' external appearance is identical to that of Humans, but they have a much more complex cellular structure, which allows them to absorb enormous quantities of sunlight. When exposed to a sun much larger than their own, like Earth's Sol, Kryptonians get so much energy in their cells that they become virtually invunerable and capable of superhuman strength and speed, super acute senses (especially hearing), and possessing such abilities as flight, heat vision and x-ray vision. Which, if any, of these abilities are natural and which are only possible under Earth's conditions, is still unclear. Kryptonians are deadly vulnerable to kryptonite, a radioactive substance formed from the remains of their destroyed homeworld.

The Kryptonian technology was mostly based on giant self-grown crystals which were very common on their planet and could be used to store information. These structures might have been natural or artificial, or a combination of both. Kryptonians were a very xenophobic species which hardly ever left their planet, making Superman (known on Krypton as Kal-El) the only Kryptonian left when the planet exploded. Kryptonian Dogs were kept as pets by the Kryptonian race, much like Earth Dogs are kept as pets by Humans.