And in fact, the ones they use aren't very authentic. Vampires as presented on TV were really a 19th century invention (from the novel Dracula); reinvented in the 80s as sexy goth-types by Anne Rice, and then reinvented as glittery teen hearthrobs a few years later by Twilight in what can only be described as the fastest dumbest downhill slope from 'scary/cool' to 'pathetic' imaginable. And Zombies as presented on TV were really just based on Hollywood itself; though they have a few drops of historical inspiration, there was never really a historical undead that was exactly like the type of Zombies we see on The Walking Dead.
So I thought I'd throw TV execs a few pointers, of some fascinating and freaky historical undead from all sorts of different cultures. Let's take a look at a list of creatures that could easily fill up a whole fall lineup for cable TV!
One of those very heavily-altered inspirations for the TV zombie, Ghuls originated in middle-eastern mythology. From them, we get the English word "ghoul." Ghuls were hideous creatures who hung around cemeteries and eat corpses, but also love the flesh of the living. Technically though, Ghuls aren't even really undead. In Arabian lore they were never actually humans, they were a type of evil genie, and were created by the Devil. In some stories, Ghuls can also shapeshift into hyenas, or can take the appearance of the person they most recently ate. It's also said they especially like to eat the flesh of children, which sounds to me like something Arab moms used to tell their kids to scare them into behaving.
From Indian mythology, Vetala were actually a type of evil spirit that would enter the corpse of a dead human. The animated corpse would then hunt living humans, especially friends and family of the deceased, and drain them of their life energy (in many versions of the story, by drinking their blood). In that sense, you could say the Vetala is potentially one of the oldest versions of the vampire myth. According to legend, only great holy men could banish a Vetala.
Another undead creature from India, the Preta are humans who became undead because in their lives they were extremely greedy, covetous, or jealous. So they are reborn as living-dead skeletal monsters with mummified skin and distended bellies who suffer from an insatiable hunger.
Just as Ghuls hung out in cemeteries, Preta were said to hang out in Indian charnel grounds (the place where corpses were laid out for cremation), but sometimes can also be found in isolated barren wilderlands. In some stories, Preta eat corpses, dung, or other awful things (typically taboo in Indian religions); but in others they lust for human flesh.
Revenants were the classic undead of Western Europe in the Middle Ages. Recently, a medieval village was found in England where many buried corpses were discovered to have been decapitated or dismembered, to prevent them from returning as Revenants.
In some stories, Revenants rise from the dead because they committed suicide, or because they were unbaptized or buried without proper last rites. In others, because they made a pact with the devil. When they rise, they will return to the places of their old lives, and often attack people they knew from life. According to ancient lore, they can only be killed if their head is severed from their body, and an iron or hawthorn nail driven through their heart.
5. Phantom Knights
Also from Europe, phantom knights were the ghostly spirits of warriors who had committed great sins in life and died without proper funerary rites. They were said to appear in isolated places, especially ancient pagan sites like stone circles or hill-mounds. Sometimes they would only appear on the full moon or at midnight, and would seek to challenge some mortal warrior to a duel. The most famous example in English folklore is probably the phantom knight of Wandlebury Hill, near Cambridge. Headless Horsemen, who existed in European legend but were brought over to the USA in "Sleepy Hollow," is a popular variant of the Phantom Knight.
6. Aztec Undead (Cihuateteo)
Many parts of the Americas had their own undead. In Aztec tradition, one of the scariest were the Cihuateteo. These were all female, created when women died in childbirth. They would haunt crossroads, and steal away children. They'd also drive living women mad, and try to make living men have sex with them.
7. Hopping vampires (Jiangshi)
The Hopping Vampires, which you might know if you're a fan of Hong Kong cinema, seem kind of silly but were meant to be very dangerous. They would hop rather than walk because their bodies were stiff like a corpse. According to ancient texts, Jiangshi were mainly created either by evil necromancers, or when someone wasn't buried properly; but sometimes might arise when a bolt of lightning hits a grave.
In Chinese mysticism, the soul has two parts: the Hun and the Po. The Hun is our higher spirit, and separates from the body after death. The Po is the baser instinctual part of us, and remains in our corpse after we die, so Jiangshi are just amoral creatures of instinct. In some modern movies, they drink blood like literal vampires, but that's a novelty. In older texts, they would drain your Qi or life-force. They can be immobilized if you stick a Taoist magical paper talisman to their face.