The biology of vampires

João Pedro O. Krizek & Marcus Vinicius D. V. Muller

Instituto Federal de Educação, Ciência e Tecnologia de São Paulo, São Paulo, SP, Brazil.

Emails: jpokrizek (at) gmail (dot) com; marcusvdvmuller (at) gmail (dot) com

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Vampires are mythological and folkloric creatures that have been catching people’s attention for centuries (Fig. 1). They (fortunately or unfortunately) do not exist in the real world, but our intention in this article is to conduct a scientific interpretation of vampires as if they were real. Here, we examine some possible scientific explanations for vampirism, if it existed, particularly by looking at the biology of these fascinating creatures and proposing explanations based on real-world scientific knowledge.

In the first section, we discuss what could be the cause and origin of vampirism in humans. In the second section, we analyze different aspects of the vampire phenotype, such as aversion to garlic, sensitivity to sunlight, anticoagulant and anesthetic production, aversion to religious symbols, and others. In the third section, we look at how the fear of vampires and other imaginary creatures might be related to the evolutionary history of our species. Finally, in the fourth section, we approach vampirism from the perspective of criminal psychology, briefly discussing the biography of three real-life murderers who have their atrocities related to vampirism: The Impaler, The Blood Countess, and The Vampire of Sacramento.

Figure 1. Vampire, by Edvard Munch (1895). Public domain.


Vampirism, in humans, could be a syndrome caused by a virus, which we shall call NHV (Nosferatean Human Virus). When a vampire bites a human, if the victim does not die, they become a vampire. A possible explanation for this is that, upon contact with the victim’s blood, a vampire’s contaminated blood or saliva can transmit the NHV.

Based on the biology of real viruses, we hypothesize that the NHV is approximately 90 nanometers in diameter. Its genetic material is made up of double-stranded DNA composed of 666 genes. The capsid – the protein coat that surrounds the viral genome – has a complex shape, resembling an inverted cross. A membranous envelope surrounds the capsid of the NHV. Viruses recognize, and subsequently infect, host cells by a “lock-and-key” fit between viral envelope proteins and specific receptors on the outside of cells (Reece et al., 2015). The viral envelope of NHV can contain numerous proteins, which function as “master keys” and, therefore, allow this virus to recognize and infect practically any human cell, especially the host’s neurons.

The origin of the vampire virus could have happened through a natural process called spillover. This is a process in which a pathogen – a disease-causing being – passes from one host species to members of another species; after this event, the pathogen can thrive, undergo adaptations, and propagate among the individuals of the new host species (Quammen, 2012). Thus, our hypothesis is that the NHV is a modified version of a virus that remained trapped for a long time in an extinct species of vampire bat, and that managed to migrate and adapt to human hosts. In real life, by the way, bats are one of the main reservoirs for viruses that are potentially terrible to humans. Hendra virus, Marburg virus, the rabies virus, most likely the Ebola virus, Nipah virus, and the SARS virus are all examples that appear to have originated from bats (Quammen, 2012).

In biology, we use the term “genotype” to designate the genetic makeup of an organism. “Phenotype” is used to refer to the totality of observable characteristics of an organism, which are the result of the interaction of its genotype with the external environment. Pale skin, sharp teeth, red mouth, aversion to garlic, and thirst for blood are all examples of characteristics that make up a vampire’s phenotype. The phenotype is the external manifestation of a “hidden” genotype. However, much of a vampire’s phenotype seems to be caused not by the manifestation of the genetic makeup of their human cells, but by the manifestation of the genetic makeup of the NHV “overwriting” parts of the human genotype. In other words, pale skin, sharp teeth, red mouth, aversion to garlic, and thirst for blood are all characteristics that occur after NHV infection and are caused by it. Vampirism, therefore, probably is a case of extended phenotype (Dawkins, 2016): the characteristics of vampirism are programmed into the NHV genotype, but extend beyond its viral body and manifest in its human hosts.

Through its extended phenotype, the NHV can manipulate its hosts’ brain cells, making them thirsty for blood. Since this viral species is transmitted through the exchange of contaminated body fluids, by provoking bloodlust in humans, the NHV increases its chances of spreading. The ability of the NHV and other parasites to act as puppeteers of their hosts’ behavior is simply a way that parasites have evolved to increase their survival and reproduction rates (Ricklefs & Relyea, 2014). Parasites can control the behavior of different animals. Carpenter ants (Camponotus leonardi), for example, live in nests in the forest canopy in Thailand. Ants sometimes move from the canopy to the ground, where they can be infected by the zombie-ant fungus (Ophiocordyceps unilateralis). Then, an infected ant moves into the understory vegetation, approximately 25 cm from the ground. Here, the “zombie ant” clings to a leaf and dies. Then the fungus produces a reproductive structure outside the ant’s body, where the “spore rain” occurs and contaminates other ants on the forest floor (Andersen et al., 2009; Ricklefs & Relyea, 2014).



In this section, we analyze different aspects of the vampire phenotype.

Aversion to garlic. The fact that garlic works as a repellent against vampires is part of traditional knowledge. This could happen due to the presence of some chemical substance that occurs in this plant. Scientifically, compounds produced by plants are classified into two groups: primary and secondary metabolites (Evert & Eichhorn, 2013). Primary metabolites are molecules found in all plant cells and are essential for all plant life – examples include proteins and nucleic acids, DNA and RNA. Secondary metabolites, in turn, are restricted in their distribution, both within a plant and between different plant species, and confer different benefits to the plants in which they occur. Some secondary metabolites are known as alkaloids, which are pharmacologically important substances that exert remarkable physiological and psychological effects in humans. Examples of alkaloids include morphine, cocaine, caffeine, and nicotine. Garlic and onions are part of the botanical family Amaryllidaceae. Plants in this group produce “amaryllis” alkaloids (Judd et al., 2008). Our hypothesis is that this different type of alkaloid triggers some exacerbated immune response in vampires, causing headaches and sensory overload. Therefore, the different species of Amaryllidaceae are important weapons of protection against vampires.

Sensitivity to sunlight. Vampires are quite sensitive to sunlight. A possible explanation for this is that these creatures have a blood disorder called erythropoietic protoporphyria. The most visible symptoms of erythropoietic protoporphyria in humans are lesions and blisters formed on the skin caused by contact with light (Lecha et al., 2009); the same could happen with vampires. To alleviate the symptoms of this disease, vampires usually only leave the house at night, which explains the fact that they are pale. Carriers of erythropoietic protoporphyria are also chronically anemic, which would justify their blood-rich diet, and have reddened mouth and teeth due to irregular production of the heme pigment, which gives erythrocytes (red blood cells) their color.

Superhuman strength. Vampires are stronger than uncontaminated humans. This could probably be due to muscle structure: a vampire’s skeletal muscle could have longer fibers than the human equivalent. Furthermore, in real life, geneticists have identified some genes that contribute to the development of certain muscles in primates, such as chimpanzees, and found that they are turned off in humans, excluding exceptional athletes. Maybe the same is true for vampires. For example, the gene called MYH16 contributes to the development of large jaw muscles in primates. In humans, MYH16 is disabled; however, in vampires, MYH16 could become activated. Several humans have also lost another muscle-related gene called ACTN3. People with two functional versions of this gene are super speedsters (Hawks, 2009) – which could include vampires.

Nocturnal habit. In addition to avoiding exposure to sunlight, nocturnal habits can have other advantages for vampires (Crawford, 1934). In nature, nocturnal habits allow animals to avoid daytime predators. Harvestmen, crickets, beetles, moths, ants, bats, rats, and mice are animals that can find in nocturnal activity a way to avoid many daytime enemies. Similarly, vampires could avoid human hunters. Secondly, a nocturnal habit allows for capturing prey more easily. Uncontaminated humans are typically diurnal, and they are more vulnerable to being preyed upon at night during sleep; besides, human eyes do not see as well in the dark. Alligators, anacondas, vipers, owls, most bats, raccoons and female mosquitoes prefer to hunt at night for the same reason. Thirdly, a nocturnal habit makes it easier to detect victims by smell. Millipedes, cockroaches, and beetles are creatures with a well-developed sense of smell, and odors linger longer in the air at night, due to the higher humidity and the relative absence of updrafts; similarly to these animals, vampires must have a developed sense of smell. Furthermore, nocturnal vertebrates have eyes with a retina rich in rods – cells sensitive to low-intensity light. Bats, dogs, cats, crocodiles, and lemurs also have the tapetum lucidum (Latin for “bright tapestry, coverlet”), a membrane positioned inside the eyeball that acts as a retroreflector increasing the light available to the rods (Crawford, 1934). Due to their nocturnal habit, vampires are also expected to have a rod-rich retina and a tapetum lucidum.

Production of carmillin. Animals that feed on blood produce anticoagulant substances. For example, leeches produce a substance called hirudin (Markwardt, 2002) and vampire bats produce a substance called draculin (Apitz-Castro et al., 1995). Therefore, we assume that vampires produce something similar to the draculin found in bats, which we call carmillin, secreted in their saliva. It’s probable that, like draculin, carmillin is formed by molecules of glycoproteins – proteins bound to one or more carbohydrates (Fernandez et al., 1998).

Production of vampirin. In addition to anticoagulants, leeches and vampire bats produce other substances in their saliva, including anesthetics – to stop the victim from feeling pain – and vasodilators – to increase the diameter of the victim’s blood vessels and increase blood flow. We assume that human vampires produce a special type of anesthetic, which we call vampirin. In addition to removing pain, vampirin can produce euphoric sensations and hypnotic states in victims.

Production of dracu-telomerase. The cells of any animal’s body are constantly being renewed. Old and worn-out cells are replaced by new cells through the process of cell division – when a cell separates into two daughter cells (Alberts et al., 2013). When animal cells are grown in the laboratory, however, they stop replicating and die after a few generations (except for cancer cells). This happens because, with each cycle of cell division, the ends of the chromosomes, called telomeres, undergo shortening. In this way, telomeres tend to decrease in size as an individual gets older, putting a limit on their longevity. However, there is a dilemma: if the chromosomes of germ cells – those that produce sperm and eggs – became shorter with each cell division, essential genes would end up being deleted in the sex cells produced. This does not happen because an enzyme called telomerase promotes the elongation of telomeres in germ cells, restoring their original size and compensating for the loss that occurs during cell division (Reece et al., 2015). Except for germ cells, telomerase is inactive in most human cells; however, we hypothesize that, in vampires, a special type of telomerase is found in all cells, which we call dracu-telomerase. This very efficient enzyme enables the great longevity of vampires.

Diet and physiology. Vampires seem to be obligate hematophagous, meaning that they necessarily feed on the blood of other animals. Blood is a challenging nutrient source because it consists of a liquid phase, called plasma, which corresponds to approximately 78% of the blood, and a solid phase – constituted by the blood cells –, composed of 93% protein and only 1% carbohydrates, providing very low levels of vitamins and lipids (Zepeda Mendoza et al., 2018). In this way, vampires probably have numerous important physiological adaptations to this hyperproteic feeding habit. In mammals, energy flow, protein metabolism, and renal excretion processes constitute a set of closely related functions. The formation of urine begins with the filtration of body fluid in the kidneys. Nephrons are the functional units of the kidneys. Each nephron consists of a single long tubule and a ball of capillaries called a glomerulus. The blunt end of the tubule, expanded in the shape of a cup, is called Bowman’s capsule and surrounds the glomerulus. The filtrate is formed when blood pressure forces fluid from the blood in the glomerulus into the lumen of Bowman’s capsule (Reece et al., 2015). When proteins and nucleic acids are metabolized, they produce carbon dioxide, water, and urea (Schmidt-Nielsen et al., 1997). High-protein diets raise the concentration of urea in the blood. This compound can be toxic to cells and tissues, so it should not accumulate in the body. Thus, hematophagy in animals has over time selected for evolutionary specializations that would solve the problem of renal failure. Similar mechanisms must be in place in vampires. Some studies show that high-protein diets reflect on the size of the kidneys, making them larger, due to the greater workload received by the organ, a consequence of increased filtration of protein metabolites, especially urea (Gopal, 2013; Linhares et al., 2021). In this sense, vampires’ kidneys might be proportionately larger, relative to body size, compared to uncontaminated humans’ kidneys. Additionally, both the glomerular area and volumetric density of glomeruli are probably greater in vampires.

Vampire microbiota. In addition to morphophysiological adaptations, host-associated gut microbiota may play an additional, possibly equally important, role in the evolution of vertebrate dietary specialization (Ley et al., 2008). Microbiota is a symbiotic relationship between various microorganisms and their hosts. This microbiota contributes to the health and well-being of the host by generating microbial products and inhibiting the growth of pathogens. In contrast, the host provides several microenvironments that allow microbial growth. Colonization begins as animals are exposed to microorganisms from birth. An animal’s body is not a uniform environment. Each region of the body differs chemically and physically from each other, being a selective environment, where the growth of certain microorganisms is favored or not (Madigan et al., 2014). Although the functional role of the gut microbiota of vampire bats has not been studied in detail, analyses with hematophagous invertebrates have shown that the gut microbiota contributes to the digestion of consumed blood, supply of nutrients absent in the blood (Graf, 2001), and immune protection (Indergand & Graf, 2000; Zepeda Mendoza et al., 2018). In humans, the composition of the gut microbiota and diet influence the type and number of compounds produced. Among these products are vitamins B12 and K, which are essential and not synthesized by humans, being produced by the intestinal microbiota and absorbed from the colon (Madigan et al., 2014). One study has isolated bacteria of the species Aeromonas hydrophila from fecal samples of vampire bats. These bacteria are hemolytic and thus, can aid in the digestion of blood (Hanning & Diaz-Sanchez, 2015). Studies also suggest that bacteria species of the genus Helicobacter help in the production of the urease enzyme, necessary in the metabolization of urea that is concentrated in vampire bats (Song et al., 2019). We hypothesize that the composition of the microbiota of human vampires is not entirely different from that of humans. Both must share some species, but at the functional level, they can be almost completely distinct. Thus, it’s probable that the gastrointestinal tract of human vampires has a microbiota composed of microorganisms capable of assisting in the metabolization of ingested blood proteins, producing some nutrients absent in the blood, and generating protection against pathogens.

Aversion to religious symbols. We assume that the idea that vampires have an aversion to religious symbols – such as holy water and crucifixes – is a superstition. Despite this, we believe that vampires have an aversion to any object made of silver, including religious symbols made of it. This is probably because silver triggers an allergic response in these creatures. An allergy is an exaggerated response to a particular antigen – a molecule, generally considered foreign by the body and which induces the formation of antibodies. In vertebrates, mast cells produce histamine and other molecules that cause inflammation in response to infection and in allergic reactions. An acute allergic response can trigger a life-threatening reaction called anaphylactic shock. Here, substances released by mast cells trigger the contraction of the bronchioles in the lungs and the dilation of peripheral blood vessels, causing a sudden drop in blood pressure and inability to breathe. In this way, death can occur in a few minutes. In humans, bee venom, penicillin, peanuts, and seafood are some substances that can cause anaphylactic shock. In vampires, silver could be one such substance. People with severe hypersensitivities often carry syringes containing the hormone epinephrine, which quickly counteracts the allergic response (Reece et al., 2015).



The roots of most vampire stories go back to the superstitions around the world. In Eastern Europe, we can find stories of the reanimated dead known as revenants (Fig. 2), who came out of the grave to torment their relatives and neighbors. In Norse mythology, there are stories of creatures known as draugr, beings of superhuman strength who smelled foul and looked hideous, and who returned from the grave to haunt the dreams of the living. In Greek mythology, there is the myth of Empusa, daughter of Hecate, who attracted young men at night and feasted on their blood and flesh. Another Ancient Greek story involves Lamia (Fig. 3), lover of Zeus, cursed by his wife Hera and doomed to become a child-eating demon. In Mesopotamian and Judaic mythology, there is the myth of Lilith (Fig. 4), supposedly the primordial she-demon, who was often depicted as subsisting on the blood of babies (Mahnke, 2017).

Figure 2. Drawing of an undead that rose from its tomb. Unknown author (ca. 1500). Public domain.
Figure 3. The Kiss of the Enchantress, by Isobel Lilian Gloag (1890), depicts Lamia as half-serpent. Public domain.
Figure 4. Lilith, by John Collier (1889). Public domain.

 The fear of vampires does not reflect empirical reality, but the psychology of our ancestors. Many of our fears bear little relation to the objective dangers of the modern world but are remnants of our species’ evolutionary history. Many people are afraid of flying, although traveling by car is eleven times more dangerous (Lewis, 1990). Some people are afraid of sharks, although they are four hundred times more likely to drown in their bathtub (Ropeik, 2010). Activists rightly fight for a ban on pesticide residues and food additives, even though they pose minimal cancer risks compared to the many natural carcinogens that plants have evolved to stop herbivory (Ames et al., 1990). Such risks are misestimated because they stem from our innate fears of heights, confinement, predation, and poisoning (Pinker, 2002). Other common fears are storms, large carnivores, darkness, blood, strangers, deep water, and leaving home alone – situations that endangered our ancestors. Fear is the emotion that enabled our ancestors to deal with the dangers they might encounter (Pinker, 1997).

In his book The Descent of Man, Darwin (1871: 43) reported how captive-bred monkeys exhibit a strong instinctive fear of snakes: “I then placed the stuffed [snake] specimen on the ground in one of the larger compartments. After a time all the monkeys collected round it in a large circle, and staring intently, presented a most ludicrous appearance. They became extremely nervous; so that when a wooden ball, with which they were familiar as a plaything, was accidently moved in the straw, under which it was partly hidden, they all instantly started away. These monkeys behaved very differently when a dead fish, a mouse, and some other new objects were placed in their cages; for though at first frightened, they soon approached, handled and examined them.

Similar to Darwin, Hebb (1946) found that chimpanzees scream when they see a snake for the first time. These behavioral responses are ingrained in these primates. The best evidence that fears are adaptations – and not just errors of the nervous system – is that animals that evolve on islands without predators (like dodos and kiwi) lose their fear and are easy prey for any invader (Pinker, 1997).

In his account, Darwin (1871: 43) observed that, despite the fear, “One of the monkeys immediately approached, cautiously opened the bag a little, peeped in, and instantly dashed away”. The ape was taken by curiosity, in the same way that humans are drawn to horror, provided they are safe – for example, within fiction. Fear and fascination intertwine when there is no real danger. Our attention is preferentially captured by evolutionarily relevant dangers, and horror fiction monsters such as vampires capitalize on this tendency. It is obvious that such creatures did not exist in ancestral environments, but vampires represent an imaginative combination of threats that existed in prehistoric times – such as the threat posed by mammalian predators with sharp teeth and thirst for blood (Clasen, 2014).

The fascination that many people feel with vampires is likely the result of an adaptive tendency to pay attention to these dangerous creatures and learn about their behavior. This is the idea of the “Jurassic Park hypothesis” proposed by Barrett (2015). According to it, the modern horror story functions as a technology that involves monstrous beings that allow us to exploit an adaptive motivational system to learn about danger and to calibrate our responses to it. Consuming horror stories has all the benefits of learning about dangers and responses to it but without the risk of actual harm (Clasen, 2012). This probably also explains why horror story fans have shown themselves to be more psychologically prepared when facing the COVID-19 pandemic (Scrivner et al., 2021).

Most vampire stories have their genesis in our psychology and the human need to explain what we don’t understand. For example, ancient Europeans used the vampire myth to explain why a corpse didn’t decompose at the normal, expected rate. Before the development of modern medicine, porphyria and rabies were diseases used as an explanation for the growth of vampire mythology, because of the similarities between these diseases and vampiric characteristics. Today, we have a much deeper scientific understanding of how these diseases work, and what happens to the body after a person dies (Mahnke, 2017). However, the answers don’t dispel all the myths. Vampire stories refuse to die, and the fascination and fear of these creatures will always live within us.


In folklore and literature, the term “vampire” describes supernatural beings that conjure up the image of bloodthirsty “undead”. In the field of psychology and criminology, however, “vampirism” has a very different meaning: it is a paraphilia in which people derive intense sexual pleasure from the act of drinking human blood (Schechter, 2003). As perverse as such sexual practice may seem, not all vampires are psychopathic criminals. Despite this, some of the most famous serial killers in the history of criminology possibly have practiced vampirism in addition to other abominations (Schechter, 2003). Three of these serial killers have their biographies summarized here: The Impaler, The Blood Countess, and The Vampire of Sacramento. The three are historical figures linked to vampirism, who broke with previous folk versions and promoted the modernization of these creatures in the media and literature.

Vlad III, The Impaler (1431–1476)

The most prominent figure linked to the modern idea of the vampire is Vlad III (Fig. 5), who ruled the Romanian principality of Wallachia, south of Transylvania, from 1456 to 1462. His father was known as Dracul, which in Romanian means “dragon”. Vlad’s nickname, Draculea, means “son of Dracul”. Although he was not a true serial killer, Vlad killed his enemies with immense sadism. He became known as Vlad Tepes, which means “Vlad, The Impaler” because he preferred to execute his enemies by impaling them on stakes. It is Vlad’s malevolent reputation that impressed Bram Stoker and motivated him to use The Impaler as inspiration for his legendary vampire (Mahnke, 2017).

Figure 5. Vlad Ţepeş, the Impaler, Prince of Wallachia. Unknown author (16th century). Public domain.

When impaling his enemies, Vlad displayed bewildering creativity. Using the weight of his victims as they slid down an oily, spiky stake, he impaled them through the mouth, anus, heart, or navel. Blinding, burning and scalping his victims were also some of his methods. According to legend, on April 2, 1459, in Brasov (Transylvania), he ordered the impalement of thousands of Saxons, with the stakes arranged around a table on which he calmly dined around the carnage (Schechter, 2003).

Modern historians, however, have discredited this hideous image of Vlad as a major slanderous critique exaggerated by his enemies and argue that Vlad’s actions must be interpreted in the proper historical context. Despite being a remarkable leader, Vlad was likely cruel but no more so than other aristocratic warriors of his time (Schechter, 2003).

Elizabeth Báthory, The Blood Countess (1560–1614)

Born on August 7, 1560, at the foot of the Carpathian Mountains, Elizabeth Báthory (Hungarian name: Báthory Erzsébet) (Fig. 6) belonged to one of the oldest and noblest Protestant families in the Kingdom of Hungary. Heiress to absurd wealth, Elizabeth received a classical education, being fluent in Hungarian, Slovak, Greek, Latin, and German.

Figure 6. Copy of the original (lost) portrait of Countess Elizabeth Báthory. Unknown author (probably 16th century). Public domain.

Some rumors claim that as a child, Elizabeth suffered from terrible epileptic seizures. It is also likely that she witnessed various acts of violence during her childhood, including mistreatment of servants and occasional public executions. At the age of ten, she became engaged to Count Ferencz Nádasdy, a warrior and member of another powerful Hungarian family, and moved into his castle, which had a torture dungeon. On May 8, 1574, the bride and groom were married. Nádasdy, a lover of battles, spent little time on their property. Because of his cruel reputation, he has been nicknamed the Black Knight of Hungary.

Due to her husband’s travels, Elizabeth and Nádasdy barely saw each other, and it took ten years for the couple to have their first child. When they met, the couple shared a common interest in torturing young maids. Supposedly, the earl once covered a young girl with honey so that she would be mercilessly bitten by insects. He even presented the countess with a sort of clawed glove, which she used to cut the flesh of her servants. It is therefore undeniable that the Black Knight was a strong inspiration for the psychopathic and impressionable young Elizabeth. Another possible influence on the countess was Anna Darvolya, a mysterious woman who came to stay at the castle in 1601 and who was reputed to be a witch (Telfer, 2017).

Between the time of her marriage and imprisonment in 1610, there are estimates that Elizabeth may have been responsible for up to 650 murders. Most of her victims were peasant women lured to the castle in search of employment. Additionally, several maids were constantly dying on Elizabeth and Nádasdy’s property, but the authorities didn’t care. For the ruling classes, the lives of young peasants did not have much value. At the time, the Hungarian legal code called Tripartitum limited the rights of peasants and serfs to next to nothing, while protecting the nobility who mistreated them (Schechter, 2003).

According to legends, Elizabeth cultivated the habit of killing virgin prisoners, filling a bathtub with their blood and bathing in it, as a way of preserving her youth. Supposedly, this cruel habit began when a maid made a mistake while bathing Elizabeth, the countess slapping the girl so hard that a little blood splattered her face. After cleaning it, Elizabeth would have noticed that her skin looked more youthful, producing her habit of bathing in the blood of virgins. However, apparently, this is not true. In Elizabeth’s trial transcripts, none of the servants who testified made any mention of the alleged bloodbaths (Telfer, 2017). Despite this, the Blood Countess made frequent use of whips, scissors, pliers, needles, red-hot branding irons, and peg-lined cages, though she especially liked to tear off pieces of flesh from victims with tweezers or with her teeth (Schechter, 2003).

In 1604, Nádasdy fell ill and died, with Elizabeth experiencing a prolonged period of stress. Around this time, the Blood Countess became even more fanatical about torturing and killing. For this, she had the help of Anna Darvolya, her guest; Ilona Jó, her children’s nurse; Dorka, a friend of Ilona Jó; Katalin, a washerwoman; and Ficzkó, a disfigured young man (Telfer, 2017).

Like many of the serial killers who followed her, Elizabeth became a reckless and disorganized killer. With the depletion of young peasants in the region, Elizabeth began ​​​​​​​attacking the daughters of the gentry, attracting the attention of the authorities. Condemned to be walled up alive in her castle, she probably died of starvation in 1614.

Richard Chase, The Vampire of Sacramento (1950–1980)

Born in Sacramento, California, Richard Trenton Chase already manifested, at age of five, the three factors of the Macdonald (1963) triad (important danger signs considered predictive of, or associated with, violent tendencies, particularly concerning serial offenses): enuresis (bed-wetting), pyromania (setting fires), and early sadism (usually in the form of cruelty to animals). As a child, Chase tortured and killed small animals – birds, cats, and dogs – drank their blood, and devoured their intestines. He also occasionally injected rabbit blood into his veins. He believed that the blood of these animals would prevent his blood from turning to dust (Schechter, 2003).

Chase was affected by the rare Renfield’s syndrome, so named by psychologist Richard Noll (1992) in reference to Dracula’s assistant who fed on live animals: “My homicidal maniac is of a peculiar kind. I shall have to invent a new classification for him, and call him a zoophagous (life-eating) maniac. What he desires is to absorb as many lives as he can, and he has laid himself out to achieve it in a cumulative way. He gave many flies to one spider and many spiders to one bird, and then wanted a cat to eat the many birds. What would have been his later steps?” (Stoker, 1897: 59).

Renfield’s syndrome worsens through four stages (Casoy, 2017). In the first stage, due to an incident, the child associates the taste or sight of blood with something attractive; in adolescence, there is a correlation between this attraction and sexual matters. In the second stage, the person drinks their own blood (hematophagy), often in self-harm. Then, the person drinks the blood of animals (zoophagy). Finally, the person drinks human blood, usually stolen from hospitals or laboratories; in rare cases, the person kills to achieve his goal. Such compulsion is associated with a strong sexual component.

Diagnosed as a paranoid schizophrenic and after spending several years living in mental institutions, in December 1977 Chase shot and killed his first victim, Ambrose Griffin, a middle-aged man who he encountered on the street. Then, he started breaking into houses. In January 1978, Chase killed a pregnant woman, Teresa Wallin, at her home, dismembered her body, and drank her blood using an empty yogurt cup. Circles of blood were found around the victim’s body as if a wet bucket had been moved around the corpse. Four days later, he murdered Evelyn Miroth, her six-year-old son, and a visiting friend. The autopsy revealed that the woman was sodomized; a large amount of sperm was found in her rectum. After Miroth died, Chase stuffed her mouth with animal feces (Casoy, 2017). Chase also kidnapped Miroth’s nephew, who was 22 months old. The child’s corpse was found in an abandoned box in a vacant lot.

A classic disorganized offender, Chase left footprints and several clues wherever he went. When the police found his apartment, they found everything covered in blood, including the blenders that Chase used to prepare drinks with blood and guts. The Vampire of Sacramento was then indicted for six murders and sentenced to death in a gas chamber. He told the FBI criminalists that he killed to preserve his own life. He claimed that he needed to replenish his blood, which was turning to sand after being poisoned by his mother. He also claimed that he was being pursued by Nazis who were associated with unidentified flying objects, who telepathically commanded him to kill. On Christmas 1980, Chase died by suicide by overdosing on Sinequan, a medication to treat depression and hallucinations (Schechter, 2003).


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We would like to thank the team of the Journal of Geek Studies for extended support and guidance.

About the authors

João Pedro O. Krizek is a biologist interested in ecology, sociobiology, and the philosophy of biology. He likes horror movies and true crime books. Member of the Ecology Department at the International Center for Vampire Extermination and Control (ICVEC). Under the guidance of Dr. John Van Helsing, he seeks an ultimate cure for vampirism.

Marcus Vinicius D. V. Muller is a biologist interested in zoology, physiology, and ecology. He likes horror stories. Member of the Physiology Department at the International Center for Vampire Extermination and Control (ICVEC). Under the guidance of Dr. John Van Helsing, he investigates diversity, zoogeography and evolution of tropical vampires.

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