Vampire

Vampires are a species completely identical to Humans in appearance and basic genetics but lack a heartbeat, do not age, cannot be exposed to UV light, must feed on Human blood, and cannot perish of natural causes.

The plague
Little is known about the origin of the vampire race, although it is revealed that in 2009, a plague carried by vampire bats jumped species, infecting humans. This does not necessarily mean that they originated that year, as the presence of myths describing creatures identical to them implies past outbreaks, so it is possible that the 2009 outbreak was simply one of many, and that vampires have existed for much longer than the movie explicitly states. It's probable that the Vampire virus was born from a combination of a rabies virus and certain bat genetic traits.

In any case, within ten years of the 2009 outbreak, nearly the entire Human species was transformed into Vampires, and those who were not either ran or were turned. This event resulted in Vampires becoming the dominant species, causing surviving Humans to flee. The Vampires soon learned that they needed to feed on the blood of Humans in order to survive, and thus several new corporations were created to harvest and supply blood to the masses.

Over the next ten years, the Vampires remolded the world to their needs, making new technological advances to protect themselves, such as sun-proof cars and buildings. A military force known as the Vampire Army was formed, for the sole purpose of maintaining peace, as well as capturing Humans.

Society
Vampire society is quite similar to human society, retaining the same geopolitical landscape, as seen when a newspaper is shown with the headline "German blood substitute fails", and again when the news mentions riots in London over blood rations.

Appearance
Humans infected by the vampire plague lose their heartbeat, develop pointed lateral incisors, and have reflective yellow/golden eyes. Their reflection does not appear in mirrors, but do show in cameras. Aside from this, an infected appears roughly the same as they did when they were human. Every vampire retains a bite mark from when they were turned.

However, should a vampire not drink blood for a long period of time, their ears become pointed, their teeth misshapen, their hair falls out, and their body gradually mutates into a bat-like state.

Powers and Abilities
Contrary to popular belief, vampires are no more physically powerful than humans. They do not have superhuman strength or speed, although they do have some advantages. Their hearts do not beat, and it seems they have a high resistance to pain (seen when Edward Dalton was shot in the arm with an arrow, passing all the way through, and he could talk and move around completely unhindered as if he was not in pain). This could suggest that the vampires' bodies are essentially dead. They also have the ability to rip humans apart, but only in groups and their fangs can tear into flesh easily.

Both Edward and his brother Frankie demonstrated the ability to smell human blood from several feet away, commenting on its scent. This suggests vampires have a moderately enhanced sense of smell.

Sub-Siders, or blood-deprived Vampires, are tremendously strong and can hurl a well-built Vampire across a room effortlessly. Their wings also give them the ability to cling to smooth surfaces, so they can hang from and climb almost anything. This may be the source of myths about vampires' superhuman strength and ability to turn into bats.

Weaknesses
Vampires can be killed by prolonged exposure to the sun, decapitation, and being stabbed in the heart. The latter causes the vampire to spontaneously combust.