The Most Dangerous Snakes in Vietnam

The Horned Pit Viper, scientifically known as Trimeresurus cornutus, is a venomous snake found in Bach Ma National Park and the Northern region of Vietnam. Its distinctive triangular-shaped head sets it apart from other species. The head is horned, covered with scales, and develops horns above the eyes. This snake measures approximately 50 cm in length. Its venom places The Horned Pit Viper among the most dangerous snakes in Vietnam. Due to its unique appearance, it's also known as the Devil Snake.

The Horned Pit Viper is one of the rarest venomous snakes in Vietnam, alongside the Red-tailed Green Pit Viper, the Banded Krait, and the Silver-headed Green Pit Viper, contributing to the country's ecosystem diversity. It's rarely encountered, with sightings recorded in Sa Pa (Lao Cai), Bach Ma (Thua Thien - Hue), and Phong Nha - Ke Bang (Quang Binh). The most recent sighting was in Ninh Binh during a survey conducted by scientists from Cuc Phuong National Park in April 2015. Globally, The Horned Pit Viper has only been reported in the Wuzhishan Mountains of Guangdong Province, China, bordering Vietnam. This snake's notable feature is the horn above its eyes, formed from scales. Scientists are still uncertain about the horn's purpose. The Horned Pit Viper has an average length of 50 cm, with a distinctive gray-brown body pattern. Its head is triangular, and its tail is slender. Currently listed in Vietnam's Red Book, The Horned Pit Viper holds significant scientific value and requires preservation and protection.

The Trimeresurus Stegosaurus, commonly referred to as the Dry Wood Snake, derives its name from its characteristic skin color, resembling dried leaves or branches, enabling it to camouflage for hunting and evading predators, making it challenging to identify. This snake is predominantly found in rubber plantation forests in the Southeastern region of Vietnam. The Dry Wood Snake is one of the most venomous and rarest snakes in Vietnam, with venom second only to sea snakes. It has a brown or reddish-brown color, measuring approximately 0.2 – 1 m in length and weighing 100 – 2000g, with a triangular head. Along its back, it features numerous symmetrical brown triangular patterns resembling butterfly wings. The body pattern consists of 19 to 31 dark brown triangular marks on a background of purple-brown or deep red-brown. Its appearance often resembles that of a vine snake, leading to confusion among locals and resulting in accidents. The snake typically coils within dry leaves, making it challenging to detect. After biting, the snake usually remains still, not moving, making it easily identifiable.

Most Dry Wood Snakes are highly venomous. Their venom can quickly paralyze the nervous system of prey such as mice, birds, and some other small animals, subsequently causing the victim's heart to stop beating within a few minutes after being bitten. When humans are bitten, the toxic substance from their fangs permeates into the wound, into the bloodstream, rupturing blood vessel cells, and causing dangerous internal bleeding. The Dry Wood Snake is exceptionally hazardous as it is one of the deadliest venomous snakes in Vietnam. It poses a severe threat, commonly causing accidents in tropical regions of Southeast Asia such as Thailand, Myanmar, Laos, Cambodia, Malaysia, Indonesia, including Vietnam. In Vietnam, The Dry Wood Snake accounts for 19.4% of venomous snakebite cases admitted to Cho Ray Hospital, contributing to increased mortality rates and is frequently encountered in areas with abundant rubber and cashew trees. These areas are located in the Southeastern and Central Highlands regions, Cấm Mountain (An Giang), and limestone mountainous areas in the Southern region, such as Kien Luong and Ha Tien in Kien Giang province.

This snake species resembles its name, with a green body and a red tail, making it easily distinguishable from other snake species. It mainly inhabits high mountainous areas of the Truong Son Range and deep forests in Northwest Vietnam. Recently, this species has also been spotted in Can Tho, Quang Ngai, Nghe An, and Da Nang.

The Red-tailed Green Pit Viper, scientifically known as Trimeresurus albolabris, is extremely venomous among green pit vipers, with a green body and a reddish-brown tail, reaching a maximum length of about 60 cm and weighing around 300 grams. The total length of males is 600 mm, females 810 mm; the tail length of males is 120 mm, females 130 mm. In rare cases, there are individuals living longer and weighing nearly 500 grams. This species is unique because, among its green pit viper relatives, only the Red-tailed Green Pit Viper gives birth to live young. Instead of laying eggs, after fertilization, the eggs remain inside the mother snake, forming a separate uterine sac like that of mammals. During the incubation period, the mother snake continues normal activities, but when giving birth, the area around the cloaca will rupture, and all the offspring will emerge. This also marks the end of the mother snake's life. During pregnancy, due to its specialized venom concentration, it becomes most aggressive. It spends most of its time living in trees, hence its green color for camouflage. Its vision is excellent at night but relatively weak during the day.

The Silver-headed Green Pit Viper, belonging to the genus Azemiops, is one of the most primitive and deadliest venomous snakes known to science. This snake species has an average length of about 80 cm. The population of Silver-headed Green Pit Vipers in our country is very scarce and mainly found in regions such as Cao Bang or Lang Son. Its scientific name is Azemiops feae. Among green pit vipers, this is considered the most primitive species. They inhabit high mountainous areas up to 1,000 m. True to its name, this snake has a white silver head, slightly flattened and clearly distinguished from the neck. Its body is black with many red or orange patterns. There are two large black stripes running symmetrically across the head through a narrow pinkish-white line at the front, widening at the rear.

According to information from the Vietnam Forest Creatures magazine, it has smooth scales with 17 rows on the body and a short tail. This new snake species was published in the Russian Journal of Herpetology in 2013. They were named after the Russian zoologist - Vladimir Kharin, in honor of his significant contributions to the study of reptiles and fish species in Asia. The appearance of stripes on the shiny black skin of the snake was referred to as 'elegant' by a local newspaper. This is the second species of Azemiops genus and the 60th venomous snake species out of over 210 snake species recorded in Vietnam to date.

Vogel's Green Pit Viper, scientifically known as Viridovipera vogeli, primarily inhabits dense bushes and low tree groves in the hilly areas of the Central Highlands, especially Gia Lai, Dong Nai, and Lam Dong, where this snake species is most frequently encountered. The Vogel's Green Pit Viper has an outer green color, with a lighter green underside. This snake species typically hunts at night. Also known as the Southern Green Pit Viper, this snake has a uniform green head and body, with a lighter green belly. Vogel's Green Pit Viper can be found in dense bushes and low tree groves in mountainous areas with elevations of 900 - 1500 m. Currently, its prey is not clearly understood, but it is known that this snake species hunts at night. Vogel's Green Pit Viper is primarily distributed in the provinces of Gia Lai, Dong Nai, and Lam Dong.

This is a venomous snake species, considered one of the most skilled and intelligent nocturnal hunters among snakes. In the darkness of tropical rainforest canopies, this green snake species utilizes its nocturnal thermosensing ability to capture prey. It seeks out a small tree base coiled around low branches near the ground and patiently waits for prey to pass by. With a swift strike, its sharp fangs leave little chance for the prey to escape. When bitten by a green pit viper, the victim experiences intense pain at the wound site. The pain persists for up to 24 hours after the snake bite.

Siamese Cobra (also known as Indochinese spitting cobra or Siamese Peninsula spitting cobra) is known to be a venomous snake species capable of causing lethal human fatalities. Those bitten by the Siamese Cobra will experience muscle paralysis, respiratory failure leading to suffocation, and death within 30 minutes of being bitten by the snake. In Vietnam, this snake species is commonly found in the Central Highlands and the southern region. This species does not actively attack humans but only bites when provoked or threatened. Those bitten by this venomous snake will succumb to respiratory failure and paralysis of motor activity within approximately 30 minutes due to the venom's effects. Cobras typically prey on rodents, birds, and frogs.

In Vietnam, they are mainly distributed in the Central Highlands and the southern region. The reason why cobras can flare out their hood is because they have elongated ribs, helping the snake expand its skin on the outer side of the neck, forming a shape like the front of a car. They spread their hood when encountering danger or agitation. With this behavior, the snake will camouflage its body to appear much larger than normal, intimidating its enemies. Cobras possess venomous bites. The most formidable adversaries capable of defeating cobras in the wild are mongoose, birds of prey, and humans.

The Trung Khanh Green Pit Viper, scientifically known as Protobothrops trungkhanhensis, was first discovered in the Trung Khanh region, Cao Bang. This snake species measures approximately 70 cm in length. Its primary habitat is the tropical limestone mountain rainforests. Currently, the Trung Khanh Green Pit Viper is critically endangered due to its extremely low population, listed in the red book as a species requiring conservation efforts to prevent extinction. The Trung Khanh Green Pit Viper is relatively small compared to other species in the Protobothrops genus. They inhabit elevations between 500 – 700 m.

The Trung Khanh Green Pit Viper is an endemic species of Trung Khanh, Cao Bang, Vietnam. It is characterized by its light gray-brown coloration on the back and head, which is similar in both males and females but distinct in the arrangement of scales on the body. This species has small scales separated between the head and neck, large nostrils; a slender body with keeled scales; light gray-brown coloration on the back and head, with dark brown markings on the body and tail. There are black markings near the tail, with no red markings on the tail tip.

The Earth Tiger Snake (also known as the sand tiger snake or monocled cobra) belongs to the Elapidae family. When this snake species prepares to attack its prey, its neck expands, giving it a fearsome appearance. The Earth Tiger Snake is mainly found in India, China, and Southeast Asian countries, including Vietnam. It is an oviparous species, laying around 16 to 33 eggs. Like other snakes, the Earth Tiger Snake is a cold-blooded, reptilian animal without limbs. Its body is covered in tough scales, and it sheds its skin every 2 - 3 months.

The Earth Tiger Snake has a shiny black body, resembling the color of soil, hence its colloquial name, Earth Tiger Snake. It has a 'moon-shaped' hood on its neck that it displays when angered, raising its head and hood to intimidate adversaries. There are various types of Earth Tiger Snakes, including the sand tiger snake, which is smaller in size and has black coloration. Its primary prey is rodents, contributing to ecological balance in environments where they reside. Earth Tiger Snakes are wild animals existing in nature, closely intertwined with human life. They feed on rodents, serving as natural pest controllers in agricultural fields. Humans utilize Earth Tiger Snakes for food and in traditional medicine, as their venom is processed into valuable medicinal compounds by scientists.

King Cobra has the ability to spit venom up to about 3 meters away, making it extremely dangerous. Moreover, this snake species has the capability to control the amount of venom released when biting its prey. King Cobra is regarded as a dangerous and formidable species within its habitat, although it does not actively attack humans. Depending on their habitat, King Cobras have different skin colors. Typically, snakes living in well-lit areas, near rivers, streams, and ponds have lighter-colored skin, while those inhabiting dark environments, deep forests, high mountains, and caves have darker skin.

The shedding cycle of adult King Cobras occurs approximately 4 - 6 times per year, while young cobras shed their skin every month. Usually, when living near human settlements, during the shedding period, King Cobras will seek refuge in human dwellings (especially kitchens), looking for a warm and safe hiding place, not only for food but also for warmth. Therefore, people are at risk when coming into contact with snakes, as the snakes may bite defensively. Young cobras have dark brown skin and narrow, V-shaped yellow or white stripes (which may be mistaken for kraits, but can be easily distinguished due to the broad neck bands of the King Cobra). King Cobras are usually larger than other cobra species. Furthermore, King Cobras have narrower and longer necks. A clear method of identification, visibly seen on the head, is the presence of a pair of large scales known as occipital scales, located at the back of the head. This is the arrangement of nine flattened bone plates behind, characteristic of the Water Snakes and King Snakes family, and is the unique feature of the King Cobra species.

Sea Snake, scientifically known as Hydrophiinae, possesses extremely potent venom. These snakes primarily inhabit marine environments but, lacking gills, they must regularly surface to breathe and absorb oxygen. With a flattened, eel-like shape, this species mainly resides in the coastal waters of our country. Sea snakes often have highly toxic venom. In Vietnam, various names are used for sea snakes such as 'dẻn,' 'dẻn biển,' 'đẹn,' 'hèo,' 'ông hèo,' and others. Initially, sea snakes were considered a cohesive family and distinct...Later, it was realized that sea snakes are closely related and actually deeply nested within the Elapidae family, making the classification definition unclear.

Some taxonomists have transferred all sea snakes into the Elapidae family, creating subfamilies Elapinae, Hydrophiinae, and Laticaudinae, although the latter subfamily may be disregarded if Laticauda is merged into Hydrophiinae. To date, no research work has provided convincing evidence regarding the phylogenetic relationships among different groups of sea snakes, hence the situation remains unclear. Therefore, other authors still choose to either continue working with the old and traditional arrangement or merge all genera together in the Elapidae family, without dividing them into subfamilies. Sea snakes are a group of venomous snakes living in marine environments or spending most of their time in the sea, although they have evolved from ancestors living on land.