Vampires are mythological or folkloric beings who subsist by feeding on the life essence (generally in the form of blood) of living creatures, regardless of whether they are undead or a living person. - Wikipedia
The horror world's favorite undead species seem to have it all. Favored above zombies and werewolves, these bloodsuckers almost take it all in their stride. I didn't want to wander too far out from the facts so, I made myself sit and watch/re-watch several fine vampire movies and series. And of course, I sourced for online info to boot.
Some traits, fans believe, make vampires what they are. These traits are regarded as prerequisites for identifying bloodsuckers. And although, there have been drastic modifications in the field these characteristics remain seemingly untouched and well-preserved.
1. Thirst For Blood
What else is new? Thirst for blood is the definitive vampire characteristic. The idea is really pronounced in the movie Daybreaker. I'm yet to see a movie which refutes this fact. After all, it's the reason vampires are called bloodsuckers which is a synonym of the word vampire. But I might be wrong, you know. I'm judging from the point of view of someone who's watched only over 30 vampire movies/series. They feed both on human and animal blood.
These guys are not called undead for nothing, are they? They've been dead and back, not back as humans but in a twisted form and this realm permits the abomination they became. In movies like Underworld vampires develop a technique which allows them to travel through time something called HIBERNATION. They stay frozen in a grave for a couple 100 years until the Elders activate or awaken them.
3. Hypersensitive to Sunlight
Generally, vampires avoid contact with direct sunlight. Those who risk it bust into flames or turn to ash. In Salem's Lot however, sunlight only hurts the night crawlers, it isn't fatal. The character Selene in Underworld is no longer irritated by sunlight when she gains special powers after drinking blood of the vampire forefather, Alexander Corvinus. Dracula is only weakened by sunlight.
4. Extraordinary Healing Ability
Vampires heal fast. In Blade Wesley Snipes acting as the eponymous character slices off a vampires arm and in the next scene, regeneration of the lost arm occurs. In other movies, the regeneration occurs faster, almost instantly to a point the vampire appears immune to weapons. These night crawlers also seem to heal faster in moonlight or to regenerate quicker after drinking blood.
5. Reproduction by Biting
Vampires bite to gain access to the human veins because they feed on blood. When a vampire bites, the venom is transmitted into the victim's blood stream and s/he turns. Even though, there are instances of vampire bites killing the victim outright, the fastest method of reproducing vampires is via biting. And most films and books seem to follow this idea.
6. Superhuman Ability
All works of film and literature seem to agree that vampires acquire enhanced strength when they turn. From Blade to Underworld to the more recent film Abraham Lincoln, Vampire Hunter, people do extraordinary stuff when they become vampires. And sometimes, they learn combat skills pretty fast.
Since Bram Stoker said, The dead ride fast, it seems every vampire book and movie has been trying too hard to live up to the very last letter of those words. Watch The Saga of Darren Shan and get a taste of what I'm getting at. But then, any vampire flick features fast bloodsuckers. Why not, no rational human is gonna wait around for one slow vermin to have a go at them. The adrenaline in a vamp's blood is always rushing to overflowing like a shot of morphine straight to the head.
Every vampire is susceptible to stakes. The stake might be of oak or some other exotic tree, it might be ash stake or it might be a metal of any kind, silver, steel, whatever. Thing is once the stake goes through the heart of a bloodsucker, it dies. Another thing is if the stake is pulled out before the monster either busts into flames or turns to ashes, the wound heals and the vamp lives to fight another day.
All the vampires I have read about or watched on TV have fangs. In certain situations, the canine teeth are retractable. They need these to pierce the flesh so they can suck out the juice.
All the guys with twisted lust for blood have an intense aversion for fire. Generally, flame destroys vampires of all power levels and many of their opponents wield it as a weapon when combating them. Even in the age of mass cleansing in European folklore, fire was considered a potent weapon of annihilation for vampires.
The traits listed here are true at least, eight out of ten times for all vampires in film and literature.
Keep your pen bleeding.