This is the most basic information about the undead. If you don't know this already I am amazed that you have made it this far, although I am glad you have.
What they want:
It seems that the undead have resorted back to some sort of primal instincts. At the core all they want or can do is consume flesh, idealy they want to eat yours.
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How to kill them:
This is simple, DESTROY THE BRAIN. I can't make it any simpler.
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