What is a group of vampires called?
it depends on which movie or book, but most recent ar vampire family, and vampire group, vampire relation and so on...
in Twilight it's called a coven !
It is actually called a 'Brood'.
Brood - A group of vampires gathered around a leader (usually their sire).
Sire - The parent-creator of a vampire, used both as the female and male form.
A brood may (over a long time!) become a 'clan' by virtue of lineage, bloodline.
Clan - A group of vampires who share certain mystic and physical characteristics.
A 'coven' is only correctly used in terms of witches... --noun: an assembly of witches, esp. a group of thirteen. However since more people know more about witches than vampires and since 'coven' also means 'gathering/assembly', the word coven are sometimes (wrongly) used for a group of vampires too.