Now, topics of the Supernatural that are of interest, and I wrote the headline before I gave it any thought, and because there are a lot of related things of interest I'll be brief...
Starting with Zombies, no explaining their popularity, or there is, it's Everyman's call to the Hero's journey, the realization of the mindless disorder of society that puts him at odds with it and allows him the liberty of war. That death here is more horrific than a natural death is because there's the realization that one could become one of them, the contagion of bad or diseased thought, another mindless shopper, consumer, citizen, and the death, the reanimation of the corpse, implies a loss of spirituality - that one has fallen into a deep and dire well of materialism. There is, surprisingly, a lot in common with this contemporary myth and virtually every major religion on earth, but those are thoughts I'll let you examine for yourself...
Vampires, the Undead come back to suck the blood of the living, are a curious thing as well, popular again across all cultures and times, and to explain the myth (I'll let go the reality for the moment) - I'd start with they are the memories of the deceased, come to haunt the living. Ghosts, a similar idea, are more fleeting, harmless; Vampires are by their nature malevolent and bent on corporeal harm. Vampires might be memories of the deceased that interfere with the survivors continuing on in the world, memories of violence or abuse, or a particularly gruesome disease or death, and the ceremonies designed to prevent the reanimation of the Vampires corpse, generally involving violence, might be a way to visit upon the corpse some portion of the abuse or violence they, in life, inflicted on the living. Consider Vlad the Impaler. The reality of Vampires - prematurely buried victims of disease or illness, that might through their rising infect others, might more pragmatically explain the pains taken to lay the Vampire more permanently to rest.
And finally there are Werewolves, or any of a number of their night-crawling and shape-shifting kin, on the surface, clearly rabies, underneath however a warning to beware the savagery of otherwise normal people in the evening. People who appear, by day, to be one thing, then by the evening turn into something completely different. The personification of Mans more bestial nature.
Now these are just a few fleeting thoughts to get you started, but the prevalence of the myths across cultures suggests that they carry a value or meaning, you might interpret them differently...