Answer:
The types of humanoid vampires in Dracula and Twilight are entirely fictional. Although some people identify with the concept and "want to be" vampires, there are no actual humans who are vampires. They are not real, despite being part of folklore for several centuries.
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There are, however, vampires in the animal world.
Mosquitoes and biting flies use blood as a protein source, and to form their eggs. Leeches and similar parasites use mammals as hosts.
Most similar to fictional vampires are vampire bats, leading to their use in Dracula and elsewhere. The three species of bats include Desmodus rotundus, which lives in Central and South America. These creatures can drink up to an ounce (29.6 ml) of blood from cattle and other mammals, and will attack sleeping humans. The main threat is that some of these bats carry the rabies virus.
No one is sure, but some people looks like vampires. But nobody knows if it was just gene accident or if it was real vampire...
Duh! Of course they do..... Do you even have to ask that? They live in big old castles, and party with Dracula :D