They are a hybrid between vampires and ghouls and their name could mean “after living”. The Nachzehrer is prominent in old folklore around most of the northern regions of Germany. They are creatures that come to life after being dead.
A Nachzehrer are usually created when the dead person died because of unnatural causes such as suicide or accidental deaths. The curse of turning into a Nachzehrer is not transferable like the werewolves or modern vampires that we know.
Apparently, the Nachzehrer does not really suck blood but they do devour the bodies of their family members, people near them and even their own bodies. The Nachzehrer can also kill you by ringing church bells that bring death to all who hear them and by making you come in contact with its shadow.
Now, since they are ghoul like, they are really hard to kill and can’t be killed by normal methods. You would need to have a coin and get ready to chop off their head.
The coin are said to be able to paralyse the Nachzehrer just like how Chinese vampires are with talismans. So you have to put the coin in their mouth and then make the final blow by chopping the head clean off its shoulders.
Usually, an inactive Nachzehrer could be found lying in its grave with its thumb in its opposite hand. It has its left eye opened. Apparently they have the same habit when they’re just walking about aimlessly.