How to do

From a logical standpoint, as most of my ones about mythical creatures are;

The reason why vampires have fangs is to probe skin and quickly puncture it and I'd assume they'd be hollow to better draw blood, like reverse snake fangs, they'd need the fangs to puncture because human teeth are too dull, they'd tear skin and blood'd get everywhere, potentially causing issues to the vampire as the victim would be loosing blood too fast for them to take it in

Pale due to no vitamin D, extremely low iron which causes them to have to hunt for food, human blood is the most efficient as it has everything they need, livestock blood works as well but it has lower nutritional value to them so they mostly go for humans

Most likely nocturnal due to sensitivity to the sun (burn easily, [see, vitiligo])

The reason vampires can't be seen in mirrors is because back when vampire were first imagined mirrors were backed with a thin layer of silver, which is a 'holy' metal, but as mirrors nowadays have no silver, you could potentially see their reflection

Anyone remember that vampires love counting? Well it's due to them being more susceptible to OCD and ADD

If blood lasts as long in a vampires body as it does in a human one, if a vampire completely drains its /human/ victim it'll be able to go another year before having to eat again, but if it eats just enough before issues happen it would only need to feed once a month

Vitiligo- A disease that causes the loss of skin color in blotches, making them more likely to burn

(Lolololol my dad has vitiligo, but this is done from thinking logically and from a medical standpoint, I referenced a medical dictionary that's my mothers from med school and my actual mom, who's been in the medical industry for 13+ years)