For survival purposes, vampires need to consume blood. All vampires will drink blood of some kind. If human blood is unavailable or impractical, some vampires will drink the blood of an animal. However, human blood is their preference.
Appearance of Fangs
Most of us recognize vampires having two very sharp fangs used for drawing the blood from their victims. But did you know that early vampire legend described vampires as once having hundreds of razor sharp teeth capable of tearing through thick flesh and bones in seconds? These vampires not only that drank their victim's blood, they also ate the flesh of their victims leaving little behind.
Vampires are pale because they are the dead. Hence, no blood coursing through their veins to give them a rosy complexion. Therefore, they need to disguise themselves as not to attract unwanted attention.
Aversion to Sunlight
Most folklore believe that sunlight can destroy a Vampire. Whereas others believe that sunlight's only power is the weakening of a Vampire's power. Therefore, smart vampires should stay hidden and sleep until nightfall when they would have all their supernatural powers at their disposal.
The way vampires age differs with each vampire. Some age like regular humans whereas some age extremely fast. Most vampires found in today's literature will be immortal because that tends to make for a better story. In any sense, vampires are really not immortal because all vampires can be destroyed one way or another.
Real vampires will have supernatural strength that will let them overpower any human without much effort. Their strength gives them a survival advantage.
Some vampires, though not all vampires, have the ability to influence the lesser beings, insects, animals, as well as some humans. We have seen this trait in many a vampire movie - the beautiful woman under total control of the vampire, not fighting his bite.
Some vampires can shape-shift into wolves, bats, dogs, cats, the mist and fog and other night creatures. This is how the legend of the vampire bat came into existence.
The senses of a vampire are extremely heightened from that of a regular human. They can hear, see, feel, smell, and taste more acutely. For instance, acute visual powers allow them a stalking advantage at night. They can see in the dark when their prey is blind, they can hear the tiniest sounds like the fearful pounding of a human heart, they can track using the smell of body odor. They have the uncanny ability to taste and smell fresh blood from a small scratch on their next victim's arm a mile away.