Kryptonian

Kryptonians are a sapient humanoid species 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 indistinguishable from that of Humans and other Human-like races, but they have a much more complex DNA/RNA nature and cellular structure, which allows them to absorb enormous quantities of sunlight radiation.

When exposed to a sun much larger/younger than their own and with a different frequency of light and internal radiation; like Earth's yellow dwarf Sol; Kryptonians absorb and metabolize so much solar energy in their cells that they become virtually invunerable and capable of superhuman strength, speed, agility, durability, reflexes and super acute senses (especially hearing). They also possess such abilities as flight, heat vision, microscopic/telescopic vision, freeze breath, super breath, healing-factor, and x-ray vision. Which, if any, of these abilities are natural and which are only possible under Earth's gravitational/solar conditions, is still unclear.

Kryptonians are vulnerable to kryptonite, a radioactive substance formed from the remains of their destroyed homeworld which become radiated once exposed to yellow solar radiation. Black holes consume them completely, and even their near indistructability grants them no protection from supernatural forces. They are also depowered once exposed to the precise frequency (natural or synthetic) of their native red dwarf sun.

Technology
Kryptonian technology and architecture 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. Kryptonian technology was so advanced, that they had the potential to download inscriptions onto the very electrons of their ships and metals.

Culture
The Kryptonians had two primary culture traits: science and warriorism. The political powers on the planet were governed by a council of scientists and warriors (but mostly scientists). Each noble Kryptonian family (or "House") was symbolized by perticular symbols which resemble Earth's alfabetical letters (such as "S" for El or "Z" for Zod). The red dwarf star, Rao of Krypton's solar system was worshiped as a god, but in a more scientific manner than Earth's spiritual religions. Kryptonian Dogs were kept as pets by the Kryptonian people, much like Earth Dogs are kept as pets by Humans.

The Kryptonian people were a very xenophobic race that hardly ever left their homeworld, making Kal-El (a.k.a. Superman) the only Kryptonian left when the planet exploded.

Enemies
Kryptonians were somewhat of a self promoting and indulging race and were willing to utilize lethal force to take valuables from other worlds. The planet Dheron, the fifth planet from Krypton's red sun Rao, was one such planet. Every twenty years, the planets were at war over each other's treasures. In an act of revenge, the two races disabled each other's star travel abilities. The Dheronians view theselves as the natural enemies of Kryptonians.