Six Reptiles You Might See in the Northern Territory

June 15th, 2023

Authors and ecologists Brendan Schembri, Chris Jolly and Stewart Macdonald share six iconic reptiles to look out for on your next trip to the Top End.

A copy of Field Guide to the Reptiles of the Northern Territory on a large rock, surrounded by native grasses and tanbark.


Brendan Schembri, Chris Jolly and Stewart Macdonald standing in a bushland setting, smiling and holding copies of Field Guide to the Reptiles of the Northern Territory.

Brendan Schembri, Chris Jolly and Stewart Macdonald with copies of the Field Guide to the Reptiles of the Northern Territory (Photo: author supplied).

While travelling through the Northern Territory, eagle-eyed reptile lovers are no doubt on the lookout for some of the territory’s most interesting creatures. We asked the the authors of our book, Field Guide to the Reptiles of the Northern Territory, to give us a shortlist of some of the region’s most iconic and fascinating reptiles you might see on travels through the region.

Be sure to grab your copy of the book before your next trip to the Top End and prepare to keep an eye out for these reptiles and more (from a distance of course)!


Centralian knob-tailed gecko (Nephrurus amyae)

The spectacular threat display of these unusual looking geckos involves barking, gaping with their enormous mouths wide open, and doing push ups on their spindly front legs. The gigantic head is in stark contrast to the tiny tail, tipped with a petite knob. In between, the body is covered with rosettes of spines.

These geckos are found in the central ranges of the Northern Territory, and have recently been found in nearby parts of Western Australia. They are formidable predators, easily making a meal out of anything they can fit in their capacious mouths, including other geckos.

A close up of a centralian knob-tailed gecko standing on a rock. Its gaze is intense, body at the ready.

A centralian knob-tailed gecko (Nephrurus amyae) waiting in ambush to devour unsuspecting prey. (Photo: Brendan Schembri)


Northern blue-tongue (Tiliqua scincoides intermedia)

Blue-tongues (Tiliqua spp.) or, affectionately, ‘bluies’ are familiar to most Australians. These large, impressive skinks are best known for the distinctive vividly blue tongues with which they sense the world. Many Territorians living up in the Top End before the early 2000s will have memories of seeing these huge, colourful skinks slinking around their gardens, occasionally helping themselves to uneaten dog food. Unfortunately, however, this is rarely the case these days.

The arrival of invasive cane toads resulted in dramatic declines in this ravenous species that just could not resist this toxic amphibian prey species. You’re lucky to see a northern bluey in the wild these days; however, they do occasionally still show up. Chris was lucky enough to have a mother give birth to a dozen babies on his doorstep in Rapid Creek. Keep an eye out for these beautiful lizards and be careful to avoid running them over on Top End roads.

A close-up of a northern blue-tongue standing in rocky soil.

Northern blue-tongue (Tiliqua scincoides intermedia), incredibly vulnerable to toxic cane toads, are sadly few and far between in the Top End these days. (Photo: Jules Farquhar)


Thorny devil (Moloch horridus)

Thorny devils have got to be one of the most bizarre-looking, yet coolest reptiles in the Northern Territory, if not Australia. Although they are named after a deity (Moloch) associated with child sacrifice and literally described as horridus for their ‘grotesque appearance’, nothing could be further from the truth in our eyes.

These delightful little dragons are covered from head to toe in thorn-like spines. Perfectly honed by evolution for life in the desert, they merely must stand on moist sand and can draw the water up their legs, across their bodies and into their mouths via the capillary action of microstructures in their skin. Amazingly, these iconic little thorny dragons persist on a diet of nothing but small, black ants.

Next time you’re driving roads through the Northern Territory’s arid interior—particularly the Barkly and Lasseter highways—keep an eye out for their silhouette as they slowly and jerkily stagger across the road with tail held high in their distinctive gait.

A close up of a thorny devil, with its distinctive all-over spikes, stands on red dirt.

A thorny devil (Moloch horridus) observing its surrounding with its characteristically suspicious ‘side-eye’. (Photo: Chris Jolly)


Mertens’ water monitor (Varanus mertensi)

Although they occur across northern Australia, Mertens’ water monitors are iconic in the Top End of the Northern Territory. They are an exceptionally charismatic, semi-aquatic goanna that are most commonly seen along freshwater creeks, including many popular swimming holes in places like Litchfield National Park and Berry Springs. In such areas, water monitors are exceedingly confident around people and can be seen going about their business, basking on the bank or foraging in around the water, often within meters of swimmers.

They are not fussy eaters and actively hunt for frogs, other reptiles, fish and invertebrates. While their flattened, paddle-like tail enables them to swim with ease, they’ve also been seen using it to corral fish into shallow water along the bank where they’re easier to catch.

A close-up of a Mertens' water monitor standing on a rock, sharp claws visible, its head raised and its long tail following the curves of the rock.

A Mertens’ water monitor (Varanus mertensi) surveying its local waterhole for potential prey. (Photo: Brendan Schembri)


Water python (Liasis fuscus)

Possibly the source of the dreamtime stories, the water python has an iridescent sheen to its scales that evokes the rainbow serpent. As their common name suggests, these snakes are associated with water and can be found around billabongs, floodplains, and other waterbodies.

On the floodplains around Fogg Dam, water pythons and their main prey, dusky rats, build up in such numbers as to form the highest known biomass of predators and their prey. During the wet season, the snakes follow the rats up into higher ground as they escape the floodwaters that are inundating their dry season refuges. Water pythons are also common in the suburbs of Darwin, often found raiding eggs from backyard chicken coops.

A close-up of a water python, its head peeking up above water and its body is hidden in the water under a log.

A water python (Liasis fuscus) foraging for aquatic prey. (Photo: Brendan Schembri)


White-bellied mangrove snake (Fordonia leucobalia)

Inhabiting the mangroves of northern Australia, New Guinea and South East Asia, these snakes are unique in feeding almost exclusively on crabs. They’ll even dismember crabs that are too large to swallow whole!

Although weakly venomous, they are extremely docile and essentially harmless to people. During high tides they typically retreat down crab burrows or into mud lobster mounds but emerge as the tides falls to forage for crabs on the newly exposed mud.

Throughout most of their range, they tend be a blandly coloured greyish brown; however, in the Northern Territory, they are incredibly variable and can be absolutely stunning. Brown, black, white, orange, red and yellow, or often a combination of colours forming articulate patterns occur alongside one another in areas like the mangroves of Darwin Harbour.

They are quite common and are particularly active in the morning, evening and at night during the wet season and runoff period in the Top End and can be seen from mangrove boardwalks around Darwin.

A close-up of a white-bellied mangrove snake's head with a mouthful of crab. Crab legs are sticking out the sides of the snake's mouth.

White-bellied mangrove snakes (Fordonia leucobalia) are unique among Australian snakes in feeding exclusively on crabs, the larger of which they will dismember. (Photo: Brendan Schembri)

A close-up of a white-bellied mangrove snake in the mud, curled in a tight S shape. The top part of its body is covered in bright orange scales, it's belly is white, and its head is covered in brown scales.

A white-bellied mangrove snake (Fordonia leucobalia) demonstrating one of the vast arrays of colours displayed by this species throughout the mangroves around Darwin. (Photo: Brendan Schembri)










Cover of Field Guide to the Reptiles of the Northern Territory, featuring photos of an Oenpelli python, a thorny devil, a northern knob-tailed gecko and a spotted tree monitor.

Field Guide to the Reptiles of the Northern Territory by Chris Jolly, Brendan Schembri, Stewart Macdonald

Field Guide to the Reptiles of the Northern Territory is the first regional guide to the 390 species of crocodiles, turtles, lizards and snakes of the Northern Territory, and is essential reading for wildlife enthusiasts and professional and amateur herpetologists.

It’s written by Chris Jolly, Brendan Schembri, Stewart Macdonald and is available to purchase on our website and from all good bookstores.