Persons on the periphery of the goth subculture claiming to be actual vampires but in reality being socially stunted rejects who claim the vampire aesthetic in order to build an elaborate social hierarchy around it. Often they believe they have psychic powers and they feed on the energy or "prana" of those around them, willing or not. Obese as often as not, but generally unattractive. Fake fangs abound. Fake accents too. Just be glad they're only having sex with each other.
Those vamptards over at the bar are licking my prana even as we speak; I can just feel it.
1. A Vampire who's behaving in a retarded way.
2. A retarded individual who has been turned into a Vampire, thus regenerating their brain cells.
The Vampire thought it was going to be overcast all day, so he left his sunbrella at home; he felt like a Vamptard.
Guy 1: I don't think Vampires can be mentally challenged.
Girl 1: Well, if a Vampire turns a retarded person, they'd become...
Guy 2: A Vamptarded person.