One of the most common associations with vampires is their incredible beauty. And just like every common trait, there needs to be a commonly known explanation for it. The most generally accepted theory is that vampires need to be beautiful in order to attract their victims, whose blood they will eventually drain. But in fact, vampires weren't always beautiful. They, just like other creatures of the undead, were often quite grisly and creepy-looking. It wasn't until Bram Stoker came along that people started envisioning vampires as creatures of beauty. And while Stoker may have just had his own interpretation in mind, this physical trait of the vampire was quite deliberate on Stoker's part.
Bram Stoker didn't make every vampire beautiful. In fact, it was only the female vampires in his book that showed any true beauty at all. This was because Stoker wanted to go against the grain of what was considered to be a perfect female during the Victorian period. Stoker thought that by making the female vampire stunningly beautiful, he was combining a huge danger of his own imagination, the vampire, with something that was considered to be so dangerous during the Victorian era - the thought of sex. What's ironic about that is that while he was going against most morals and beliefs at the time, these female vampires, while physically dangerous, also looked much like women from the Victorian era. Only a true artist could combine something that was so similar and so very different and make them come together as one! But Stoker wanted to do much more than just lash out on the thoughts of sex during his time. He also wanted to completely destroy the idea of the typical woman during the Victorian era.
Women who lived in the Victorian era were the stereotypical maternal nurturing types. Stoker, much like many feminists today, was apparently not at all pleased with this picture of the woman. So, while he still kept the beautiful look of the women, he also turned them into horrific monsters that killed humans and infant children, all in their need for what pleased them most - human blood.
However, Stoker still didn't allow this transformation until the women slept with the Count, when they would then change into these beautiful yet especially violent beings. So being that the woman's power still rested on first giving it over to the man, perhaps Stoker wasn't the first feminist after all!