| 1 | Brown kukri snake |
Maximum length: 95cm.
A non-venomous snake of Singapore, which is relatively widespread, yet easy to walk right past and not notice. Brown kukri snakes (Oligidon purpurascens) dwell in forests, rarely urban areas. They like pristine spots, but even in nature reserves busy with tourists, where people are watching carefully for exotic wildlife, it’s easy to completely miss them.
The reason is this species’ fossorial habitats and fantastic camouflage. The brown kukri snake lives on the forest floor rather than on branches, and spends its days burrowing in the soft upper layers of soil, shifting aside loose debris with its head. With their brown colours, they effortlessly blend in with the soil, twigs and leaves.
Even when exploring the surface, brown kukri snakes tend to stay still below rocks or rotting logs. Every aspect of this southeast Asian species is fine-tuned to stay hidden from view. Rather than attacking random people like a cobra, the brown kukri snake plays by its own rules, standing well back from the battle fray.
This species has two morphs, which commonly overlap in the same forests. The first is brown with even darker brown brands, while the second is red with orange bands. The latter is slightly easier to spot while walking past, while the first is almost impossible.
| 2 | Cox’s mud snake |
Maximum length: 137cm.
A semi-aquatic species found in Vietnam, Cambodia, and the vast majority of Thailand. Cox’s mud snake (Homalopsis mereljcoxi) is a species of muddy shores, which preys on fish and crustaceans, with a smaller helping of frogs.
This species is completely harmless, lacking a dangerous venom. Instead, their modus operandi is to lurk in shallow pools, waiting to ambush oblivious prey. There, Cox’s mud snake becomes ever more covered in muck, deliberately rolling around to cover themselves in mud from head to toe. Cox’s mud snake becomes completely disguised, and only glaring eyes reveal their presence.
All this makes Cox’s mud snake (Homalopsis mereljcoxi) very difficult to spot for a fisherman or simple villager walking past a lake. There isn’t one scale of green or bright red on their bodies. It’s all grey and brown, to maximise their muddy disguise, against both predators and prey.
Cox’s mud snakes are thick bodied, yet still surprisingly easy to walk past. They also appear in shallow wetlands, where damp vegetation increases their disguise. This species moves across land occasionally, but becomes relatively sluggish and halting.
| 3 | Smooth snake |
Maximum length: 92cm.
The third of three UK snake species, the one that few have heard of. Smooth snakes are harmless, and live in a handful of southern countries: Dorset, Surrey, possibly Berkshire and Wiltshire. They’re endangered, increasingly rare, and found in only narrow habitats.
This species is so easy to walk past that it’s now hampering conservation efforts. Even within their confirmed habitats, smooth snakes are a nightmare to search for. They live in sweeping stretches of ferns and heather, with no trees, often stretching for miles into the distance. They could be in the centre of this inhospitable habitat, or just metres from your path – it’s impossible to say.
Smooth snakes favour the most tangled sections of heathland above all. Their smooth scales evolved specifically to stop them from getting snagged. Smooth snakes avoid open spaces, and would rather weave through a neverending maze of thick roots and leaves.
Even their beige-brown patterns are optimised for blending into heathland, just as a grass snake’s are for ponds and fields. Smooth snakes also move slowly and patiently, so it’s unlikely that your eye will be caught by a sudden flicker of movement.
| 4 | Black-tailed rattlesnake |
Maximum length: 152.4cm.
It’s almost impossible to walk past a rattlesnake without knowing, for two reasons. Firstly, there’s their signature rattle, created by shaking their segmented tail scales together. Secondly, most of them are bulky brutes. The black-tailed rattlesnake is no exception, reaching a maximum length of over 1.5 metres, with a thick body.
This species is found in Arizona and New Mexico, and has a dangerously cytotoxic venom. Compared to the adventurous western diamondback, you’re more likely to walk past this species and never realise it, and that’s because black-tailed rattlers are often found on steep rocky slopes. They live in jumbled rocky fields, which they blend into perfectly.
You could be hiking up a trail in Tonto National Monument (one of their hotspots), panting and wiping sweat off your back, and never realise that a black-tailed rattlesnake was watching you the entire time. More likely, the rattler might be hiding in a dark rock crack, digesting a meal, and neither of you may realise.
If you do spot the black-tailed rattlesnake, then their namesake black tail makes them incredibly easy to recognise. This species has never caused a human death, and is also abundant in northern Mexico.
| 5 | Rainbow snake |
Maximum length: 173.3cm.
One of the most fabulously colourful species of the southeastern US. The rainbow snake (Farancia erytrogramma) has a black base covered with vivid red and yellow stripes. They often exceed 1.5 metres, yet surprisingly, this is one of the hardest large snakes to spot in the whole USA.
The main reason is their habitats, as the rainbow snake is elusive, only appearing in grasslands further afield during heavy rains. This species is found in Florida, Georgia, South Carolina and more. Within these states, they’re easily most common in scenic, shady creeks, with overhanging branches. They appear in clearer marshes occasionally, but never scenic lakes bordered by walkways and picnic benches.
Consequently, the rainbow snake is very easy to walk right past and not notice, compared to a brown watersnake or Burmese python. They’re so difficult to spot that their southern form, which lives in Glades County south of Orlando, hasn’t been seen in 70 years. Nobody is sure whether this subspecies survives.
Rainbow snakes derive most of their calories from one species, the American eel (Anguilla rostrata). Initially, they swallow their eels rapidly, before slowing down at the tail, meaning that rainbow snakes are sometimes spotted by fishermen relaxing happily with eel tail tips poking out of their mouths.
| 6 | Pale-headed snake |
Maximum length: 90cm.
This species doesn’t have the most amazing camouflage, but stays hidden thanks to instinctively gravitating towards shelter. The pale-headed snake (Hoplocephalus bitorquatus) is a forest species of eastern Australia, which occasionally appears in fields directly adjacent to forests, but requires some trees to survive. They max out at 90cm, and while they possess a sudden boost which allows them to escape dangerous situations, they generally move slowly and deliberately.
Despite their eye-catching white head, which contrasts vividly with their black body, pale-headed snakes have better camouflage than you’d expect. They have a particular liking for old, hollow tree logs, or even hollow trees which are still standing. Experts know how to search these dens, but the average person will probably walk right past the pale-headed snake, their hunger for snake encounters still unsatisfied.
Pale-headed snakes are always careful to keep their name out of newspapers. They don’t wash into houses during floods and attack people (like the eastern brown snake), or get their heads stuck in postboxes and necessitate a rescue. They’re careful to avoid drawing attention to themselves, meaning that nobody even knows to look for them, even if they enter the correct forest.
This species is moderately venomous, with a few neurotoxins, but probably in too small doses to hurt humans. No deaths have ever been recorded.
| 7 | Smooth green snake |
Maximum length: 79.7cm.
This species probably has one of the highest percentages of passers-by that fail to notice it. Smooth green snakes are common in grassy fields in the northeastern US, plus forests and grassy clearings within them. They typically measure 30-60cm, and are fully green, turning blue when they die due to the yellow pigments dissolving more rapidly.
Smooth green snakes are completely harmless, and prey on caterpillars and spiders. While many dog walkers and explorers walk past them, far fewer successfully spot them. They lurk in long grass by default, move slowly, and almost never hiss. There’s nothing to alert you if you didn’t realise the smooth green snake was there.
This species is particularly common in Ohio, Pennsylvania and Michigan. Using simple probability, the chances of spotting them are low. As a species, humans supposedly look up less commonly than they should – hence why James Bond can often escape henchmen by clinging to a ceiling. But we don’t look down and to the left that often either, which is where you’d need to look if the smooth green snake was lurking in thick tufts of overgrown grass.
Disguise is essential for this species’ survival, as their venom is incredibly mild. Overall, the smooth green snake is easily the greenest snake in the USA, alongside its southeastern cousin the rough green snake (Florida, Georgia).
| 8 | Western ratsnake |
Maximum length: 256.5cm.
The western ratsnake isn’t a shy species at all. When you’re addicted to raiding eggs from birds’ nests, there’s no way you can be. Western ratsnakes are commonly spotted in woods, parks, and even in people’s backgardens clinging to metal posts in order to climb bird feeders. It’s easy to find them on a tree branch in the back of your property, battling with angry mother birds.
Yet if the western ratsnake wants to stay hidden, it’s more than capable. Western ratsnakes not only climb trees with ease, but have a sharp sense of finding gaps in tree trunks, which have secret hollows inside. By slithering into these dark holes like a piece of spaghetti, coiling up and resting in the tree chambers within, they can completely disappear from the sight of humans.
Every day in the woodlands of Missouri and Kansas, people walk past thick tree trunks and have no idea that a western ratsnake is inside. Some may be greeted by the shocking sight of a serpent head poking its face out.
The western ratsnake is a common species, ranging from southern Minnesota to southern Texas. They’re abundant in any area they live, including in large cities like Austin and Houston. Yet they may be more abundant than even local people realise.
| 9 | Sharp-tailed snake |
Maximum length: 48.3cm.
A snake so well-disguised that people walk right past them when there’s 10-15 nearby. This is another harmless US snake, but unlike the smooth green snake, sharp-tailed snakes absorb themselves into the mulchy forest floor. They blend with the decomposing forest matter of 1000 seasons, a mixture of wet leaves, rotting logs, and soil blending into one forested mixture.
Sharp-tailed snakes are found in California, Oregon and Washington state, plus extreme southeast Canada. They have a natural inclination to gather together, and a natural inclination to lurk under cover like a millipede. Combined with an average adult length of just 30cm, it’s easy for a forest explorer to walk right past this species and not notice anything.
This is only during summer as well, the peak of their activity. In winter, they become almost impossible to find, as they retreat below the frost line into deep underground chambers.
Sharp-tailed snakes are harmless to humans except for a pointy tail, which they sometimes poke into the palm of your hand. They’re slow-moving, and up to 11 have been found together at once. There’s no foolproof way to find a sharp-tailed snake except persistence.
| 10 | Limestone eyelash viper |
Maximum length: 43.2cm.
One of the most poorly researched pitvipers in the world. This venomous species has no relation to the eyelash vipers of Central America (Bothriechis genus). Instead, they’re just another footsoldier in the vast Trimeresurus pitviper group of southeast Asia.
The limestone eyelash viper (Trimeresurus ciliaris) inhabits the Malaysian border regions of extreme southern Thailand, covering just a narrow slice of land. Due to their obscurity, they were only officially discovered by western science in 2023. It’s a rainy, jungled world they’ve found themselves, as T. ciliaris lives its life deep within rainforests, well away from human settlements.
Limestone eyelash vipers have vertical pupils with a triangular head. They’re easy to walk right past for two reasons: 1) their complex green colours, and 2) their propensity to hide among limestone boulders deep within forests, surrounded by vegetation and leaf litter. This species has juicy red patches as well, but this isn’t enough to prevent them from completely blending into the jungle.
Villagers probably walk past them constantly, while even reptile enthusiasts missed them for decades. This is to the limestone eyelash viper’s advantage, as this species is a committed ambush predator. They blend with the jungle to avoid the attention of prey, and this has the side effect of humans failing to spot them.