Mountain Horned Dragon (Acanthosaura capra) Care Sheet
The Mountain Horned Dragon (Acanthosaura capra), sometimes called the Green Pricklenape or Vietnamese Mountain Horned Dragon, is a distinctive arboreal agamid native to the humid forests of Southeast Asia.
With its prominent head spines, elongated body, cryptic green and brown colouration and prehistoric appearance, it is one of the more unusual Asian dragon species maintained in specialist reptile collections.
Unlike many commonly kept agamids, Mountain Horned Dragons are not inhabitants of hot, open, arid environments. They originate from shaded, humid forests and are frequently associated with vegetation surrounding streams and other water sources.
Their captive husbandry therefore requires careful balancing of moderate temperatures, high humidity, excellent ventilation, strong but appropriately shaded UVB, plentiful climbing structure and reliable hydration.
They can be shy and stress-sensitive, particularly when newly acquired. Captive-bred animals should be strongly preferred wherever available, as historically many specimens entering the reptile trade have been wild-caught.
Successful husbandry centres on a tall, densely furnished enclosure, moderate basking temperatures, substantial nighttime cooling, high but fluctuating humidity, excellent airflow, access to clean water and a varied diet of appropriately supplemented invertebrates.
Quick Facts
Scientific name: Acanthosaura capra
Common names: Mountain Horned Dragon, Vietnamese Mountain Horned Dragon, Green Pricklenape
Family: Agamidae
Native range: Southeast Asia, particularly Vietnam and neighbouring regions
Lifestyle: Arboreal / semi-arboreal
Activity: Diurnal
Adult length: Approximately 10–14 inches including the tail
Lifespan: Approximately 8–12+ years with excellent care
Experience level: Intermediate to advanced
Diet: Primarily insectivorous
Temperament: Generally shy, alert and stress-sensitive
Adult enclosure: Approximately 36" × 24" × 48" minimum for one adult; larger strongly preferred
Basking area: Approximately 28–30°C
Warm ambient: Approximately 24–27°C
Cool area: Approximately 20–23°C
Night temperature: Approximately 18–21°C
Humidity: Approximately 70–90% with excellent ventilation and daily fluctuations
UVB: Essential
Water: Permanent clean water plus regular misting
Handling: Minimal
Social housing: Individual housing safest
Taxonomy
Several Acanthosaura species appear under the general name “Mountain Horned Dragon”.
These include:
- Acanthosaura capra
- Acanthosaura crucigera
- Acanthosaura lepidogaster
- Other closely related species
They should not automatically be assumed to have identical requirements.
This care sheet specifically concerns:
Acanthosaura capra
Correct identification is important, particularly with imported animals.
Natural Distribution
Acanthosaura capra originates from Southeast Asia.
It is particularly associated with Vietnam and surrounding regions.
The species occurs in humid tropical and subtropical forest environments.
Natural Habitat
Mountain Horned Dragons inhabit:
- Humid forest
- Evergreen woodland
- Vegetated stream margins
- Shaded slopes
- Dense undergrowth
- Areas containing abundant branches and vines
They spend considerable time above ground but often remain relatively close to water.
Their environment is characterised by:
- Dense vegetation
- Filtered sunlight
- High humidity
- Frequent rainfall
- Moderate temperatures
- Cooler nights
Captive housing should reproduce these conditions rather than treating the species like an arid basking agamid.
Appearance
Mountain Horned Dragons have an unmistakably prehistoric appearance.
Typical features include:
- Prominent occipital spines
- Spines along the neck and back
- Angular head
- Long limbs
- Long tail
- Rough textured scales
- Green, olive, brown or grey colouration
Their colouration provides excellent camouflage among vegetation, bark and moss.
Adult Size
Adults generally reach approximately:
10–14 inches total length
including the tail.
Individual size varies according to:
- Sex
- Genetics
- Locality
- Nutrition
Males may develop more pronounced head and dorsal ornamentation.
Behaviour
Mountain Horned Dragons are relatively quiet ambush predators.
Normal behaviour includes:
- Perching on branches
- Remaining motionless among foliage
- Watching moving prey
- Short bursts of hunting activity
- Moving between shaded and exposed areas
- Drinking from leaves
- Retreating into dense vegetation
They should not be expected to display the constant activity of some terrestrial agamids.
Temperament
These lizards are generally shy rather than aggressive.
When frightened they may:
- Freeze
- Attempt to flee
- Hide
- Darken in colour
- Bite if forcibly restrained
Chronic stress can contribute to feeding problems and declining condition.
Handling
Routine handling should be minimal.
Mountain Horned Dragons are primarily observation animals.
When handling is necessary:
- Move slowly
- Support the entire body
- Avoid grabbing the tail
- Keep handling brief
- Work in a secure environment
Never repeatedly chase an animal around its enclosure simply to handle it.
Enclosure Size
For a single adult:
36" × 24" × 48"
should be considered a practical minimum.
Larger enclosures are strongly preferred.
A larger enclosure makes it considerably easier to establish appropriate gradients of:
- Temperature
- Humidity
- UVB
- Light
- Cover
Vertical Space
Height is extremely important.
Mountain Horned Dragons spend substantial time above ground.
Provide climbing opportunities throughout the enclosure.
Suitable furnishings include:
- Natural branches
- Cork bark
- Vines
- Bamboo where safely secured
- Live plants
- Artificial foliage
Branches should be positioned at multiple heights and angles.
Branch Diameter
Provide branches thick enough for the lizard to grip comfortably.
Include:
- Horizontal perches
- Diagonal climbing routes
- Vertical trunks
The animal should be able to move through much of the enclosure without descending to the floor.
Foliage
Dense foliage is essential.
The animal should be able to retreat completely from view.
Suitable reptile-safe plants may include:
- Pothos
- Ficus
- Schefflera
- Bromeliads
- Other suitable tropical plants
Ensure plants are free from pesticides and other harmful chemicals.
Visual Security
A completely exposed enclosure can cause chronic stress.
Provide visual barriers throughout the enclosure.
Dense planting also allows the lizard to regulate its exposure to:
- Light
- UVB
- Heat
- Other animals
- Human activity
Hides
Provide both elevated and lower retreats.
Suitable hiding areas include:
- Cork tubes
- Dense vegetation
- Hollow logs
- Mounted hides
- Root structures
Traditional ground-level hides alone are insufficient.
Enclosure Security
Mountain Horned Dragons can move quickly when frightened.
Ensure:
- Doors close securely
- Ventilation openings are protected
- Cable ports are sealed
- Décor cannot provide an escape route when doors are opened
Substrate
Suitable substrates include:
- Organic topsoil
- Coco fibre
- Orchid bark
- Cypress mulch
- Tropical bioactive mixtures
- Leaf litter
The substrate should retain moisture while allowing drainage.
Substrate Depth
Provide several inches of substrate.
Deeper substrate helps:
- Stabilise humidity
- Support live plants
- Provide humid microclimates
- Facilitate natural digging
- Provide nesting opportunities for females
Drainage
Because these enclosures receive substantial misting, drainage should be considered carefully.
A drainage layer may be useful in naturalistic enclosures.
Substrate should never become permanently waterlogged and foul.
Bioactive Housing
Mountain Horned Dragons are excellent candidates for properly designed bioactive enclosures.
A bioactive setup may contain:
- Live plants
- Natural soil
- Leaf litter
- Springtails
- Suitable isopods
Bioactive does not mean maintenance-free.
Water quality, waste and animal health must still be monitored.
Temperature
Mountain Horned Dragons should not be maintained excessively hot.
Their forest habitat provides substantial shade and cooler microclimates.
Basking Temperature
Provide a localised basking area around:
28–30°C
Some individuals may briefly use slightly warmer surfaces, but excessively high temperatures should be avoided.
Warm Ambient Temperature
The warmer region can generally remain around:
24–27°C
Cool Area
Provide cooler areas around:
20–23°C
The animal must always have access to cooler shaded retreats.
Night Temperature
Night temperatures can generally fall to approximately:
18–21°C
A noticeable nighttime temperature reduction is beneficial.
Overheating
Overheating is a significant husbandry concern.
Warning signs may include:
- Persistent open-mouth breathing
- Constant attempts to escape
- Remaining on the enclosure floor
- Unusual lethargy
- Persistent soaking
Always provide a substantial cool zone.
Heating
Use gentle overhead heating.
A low-wattage halogen basking lamp can provide a localised warm area.
Avoid heating the entire enclosure uniformly.
Thermostat
Heating equipment should be appropriately controlled.
Use independent digital thermometers to monitor temperatures at:
- Basking level
- Mid enclosure
- Lower enclosure
An infrared thermometer is useful for measuring basking surfaces.
UVB
UVB is essential.
Although Mountain Horned Dragons inhabit shaded forest environments, they remain diurnal reptiles exposed to filtered natural sunlight.
Provide a suitable linear UVB system.
The enclosure should offer:
- Appropriate UV exposure
- Partial shade
- Dense vegetation
- Complete shade
UV Gradient
Dense foliage naturally creates variation in UV exposure.
The animal should be able to regulate its exposure behaviourally.
UVB provision should account for:
- Lamp strength
- Distance
- Mesh obstruction
- Reflector
- Manufacturer recommendations
Lighting
Provide bright but well-structured daytime illumination.
Lighting should reproduce the contrast between:
- Brighter canopy openings
- Filtered light
- Deep shade
Approximately:
11–13 hours of daylight
is suitable depending on season.
Night Lighting
The enclosure should be dark at night.
Do not use visible:
- Red bulbs
- Blue bulbs
- Purple bulbs
If nighttime heating is genuinely required, use a non-light-emitting source.
Humidity
General humidity should typically remain around:
70–90%
but should fluctuate naturally throughout the day.
Constantly maintaining the enclosure at maximum humidity is unnecessary and potentially harmful.
Humidity Cycle
Humidity may rise substantially:
- During misting
- Overnight
- Early morning
It can then fall moderately as the enclosure warms and ventilation removes excess moisture.
This daily fluctuation is preferable to permanently stagnant conditions.
Misting
Regular misting is important.
Depending on enclosure design, mist approximately:
1–3 times daily
or use an automated misting system.
Allow some surfaces to dry partially between misting sessions.
Drinking Behaviour
Mountain Horned Dragons often drink droplets from:
- Leaves
- Branches
- Enclosure surfaces
Regular misting therefore contributes directly to hydration.
Water Bowl
A clean water bowl should still be provided.
Some individuals may soak regularly.
The bowl should be large enough for the animal to enter safely if desired.
Moving Water
Some keepers provide:
- Drippers
- Small waterfalls
- Circulating water features
These can encourage drinking but must be designed hygienically.
Decorative waterfalls that cannot be cleaned thoroughly can rapidly become sources of bacterial contamination.
Water Hygiene
Any water feature must be:
- Easy to clean
- Regularly refreshed
- Free from accumulated faeces
- Properly filtered where appropriate
Clean water is more important than elaborate water features.
Ventilation
Excellent ventilation is essential.
High humidity without adequate airflow can contribute to:
- Respiratory disease
- Skin infections
- Mould
- Bacterial growth
The objective is:
humid, fresh and well ventilated
rather than warm, wet and stagnant.
Diet in the Wild
Mountain Horned Dragons primarily consume:
- Insects
- Spiders
- Worms
- Other small invertebrates
They are visual ambush predators.
Captive Diet
Provide a varied selection of appropriately sized feeder invertebrates.
Suitable feeders include:
- Crickets
- Locusts
- Dubia roaches
- Other suitable roaches
- Silkworms
- Black soldier fly larvae
- Earthworms
- Mealworms in moderation
- Morio worms in moderation
Dietary variety is important.
Earthworms
Appropriately sourced earthworms can provide useful dietary variety.
Use worms from safe captive sources rather than areas potentially contaminated by:
- Pesticides
- Fertilisers
- Parasites
- Environmental pollutants
Gut Loading
Feeder insects should be properly gut-loaded.
Provide feeders with nutritious foods before use.
Suitable foods include:
- Leafy greens
- Vegetables
- Appropriate commercial gut-loading diets
Calcium Supplementation
Feeder insects should be appropriately dusted with calcium.
Requirements vary according to:
- Age
- Diet
- UVB exposure
- Reproductive status
Growing juveniles and breeding females require particularly careful calcium provision.
Multivitamins
A suitable reptile multivitamin can be used periodically.
Avoid excessive supplementation.
Juvenile Feeding
Juveniles can generally be offered appropriately sized insects:
Daily or 5–6 days per week
Growing animals require regular nutrition.
Adult Feeding
Adults can generally be fed approximately:
3–4 times per week
depending on:
- Body condition
- Prey size
- Activity
- Reproductive status
Feeding Enrichment
Encourage natural hunting behaviour.
Methods include:
- Releasing small numbers of insects among branches
- Varying feeding locations
- Tong-feeding selected prey
- Using suitable elevated feeding cups
Uneaten Insects
Remove uneaten feeder insects when necessary.
Crickets left loose may disturb or potentially injure resting animals.
Social Housing
Individual housing is the safest general recommendation.
Pairs may sometimes be maintained successfully by experienced keepers in sufficiently large enclosures.
However, animals must be monitored for:
- Aggression
- Feeding competition
- Stress
- Persistent courtship
- Unequal access to basking areas
Separate accommodation should always be available.
Males
Adult males should not normally be housed together.
Territorial aggression may occur.
Sexing
Mature males may develop:
- Larger heads
- More pronounced spines
- More prominent femoral pores
- More robust overall appearance
Females may remain somewhat smaller and less heavily ornamented.
Juveniles can be difficult to sex accurately.
Breeding
Captive breeding should be encouraged because established captive-bred populations reduce reliance on wild-caught animals.
Only healthy mature animals should be bred.
Females require excellent:
- Nutrition
- Calcium provision
- UVB
- Hydration
- Body condition
Egg Laying
Mountain Horned Dragons are oviparous.
Females require access to deep, moist but not saturated nesting substrate.
A suitable laying area should allow natural excavation.
Clutch Size
Females may produce approximately:
6–15 eggs
although clutch size varies.
Incubation
Eggs are generally incubated under moderate tropical conditions around:
24–27°C
with appropriate humidity.
Avoid excessive incubation temperatures.
Incubation duration can vary considerably according to temperature.
Eggs should not be rotated after laying.
Hatchlings
Hatchlings require:
- Secure arboreal accommodation
- Fine branches
- Dense foliage
- Appropriate UVB
- Gentle basking heat
- High but ventilated humidity
- Frequent misting
- Tiny feeder insects
Hatchling Hydration
Hydration is particularly important for young animals.
Provide frequent access to droplets while maintaining excellent ventilation.
Do not compensate for dehydration risk by keeping the enclosure permanently saturated.
Quarantine
All newly acquired Mountain Horned Dragons should undergo strict quarantine.
A minimum of approximately:
90 days
is a sensible starting point.
Wild-caught animals may require considerably longer monitoring.
Wild-Caught Animals
Historically, many Mountain Horned Dragons in the reptile trade have been wild-caught.
Wild-caught animals may arrive with:
- Heavy parasite burdens
- Dehydration
- Injuries
- Poor body condition
- Chronic stress
- Feeding difficulties
Captive-bred animals should be strongly preferred wherever available.
Parasite Screening
Veterinary faecal examination is strongly recommended for wild-caught or uncertain-origin animals.
Treatment should be based on veterinary diagnosis.
Do not automatically administer antiparasitic medications without appropriate assessment.
Acclimation
New animals should initially be provided with:
- Dense visual cover
- Minimal disturbance
- Easy access to water
- Appropriate temperatures
- Suitable live prey
Avoid unnecessary handling during acclimation.
Shedding
Mountain Horned Dragons shed their skin in patches.
Correct hydration and humidity generally support normal shedding.
Pay particular attention to retained skin around:
- Toes
- Tail
- Spines
- Limbs
Signs of Good Health
A healthy Mountain Horned Dragon should generally display:
- Clear bright eyes
- Strong grip
- Firm jaw
- Alert visual behaviour
- Regular feeding
- Normal climbing
- Appropriate body condition
- Smooth coordinated movement
- Normal faeces
Warning Signs
Seek veterinary advice for:
- Persistent food refusal
- Unexplained weight loss
- Sunken eyes
- Weak grip
- Tremors
- Soft jaw
- Swollen limbs
- Respiratory symptoms
- Persistent diarrhoea
- Skin lesions
- Abnormal swelling
- Severe lethargy
Common Husbandry Mistakes
Keeping Them Too Hot
Mountain Horned Dragons are forest animals that require moderate temperatures and access to cool retreats.
Small Terrestrial Enclosures
They require substantial vertical space.
Sparse Furnishings
Dense foliage and numerous branches are essential.
Poor Hydration
Many individuals rely heavily on droplets produced by misting.
High Humidity Without Ventilation
Humidity must be balanced with excellent airflow.
Permanently Wet Substrate
The enclosure should not become waterlogged.
Weak UVB
These are diurnal reptiles and require appropriate UVB exposure.
Poor Diet Variety
Do not rely exclusively on crickets or mealworms.
No Gut Loading
Feeder insects must themselves be properly nourished.
Excessive Handling
These are generally shy, stress-sensitive observation animals.
Buying Wild-Caught Animals Without Preparation
Imported animals may require substantial veterinary and husbandry intervention.
Captive-Bred Versus Wild-Caught
Captive-bred Mountain Horned Dragons should be strongly preferred.
Advantages include:
- Known origin
- Reduced parasite risk
- Better adaptation to captivity
- Reduced stress
- More predictable feeding
- Reduced pressure on wild populations
Supporting responsible captive breeding is particularly important for species historically supplied through wild collection.
Responsible Ownership
Before acquiring a Mountain Horned Dragon, ensure you can provide:
- A tall permanent enclosure
- Extensive climbing structure
- Dense vegetation
- Appropriate linear UVB
- Moderate basking heat
- Cooler shaded retreats
- High but fluctuating humidity
- Excellent ventilation
- Regular misting
- Clean drinking water
- A varied supply of feeder invertebrates
- Appropriate supplementation
- Long-term veterinary care
Suitability
Advantages
- Exceptional prehistoric appearance
- Fascinating arboreal behaviour
- Manageable adult size
- Diurnal
- Excellent naturalistic display species
- Well suited to planted enclosures
- Captive breeding achievable
Considerations
- Stress-sensitive
- Requires substantial vertical space
- Requires high humidity
- Excellent ventilation is essential
- Requires regular misting
- Sensitive to excessive heat
- Requires live invertebrate feeding
- Not suited to frequent handling
- Wild-caught specimens may have significant health problems
- Captive-bred animals can be difficult to locate
Summary
The Mountain Horned Dragon (Acanthosaura capra) is a spectacular Southeast Asian forest agamid whose husbandry differs considerably from that of hot, arid dragon species.
Successful husbandry centres on:
- Approximately 36" × 24" × 48" minimum adult accommodation
- Larger and taller accommodation wherever possible
- Extensive branches and climbing routes
- Dense foliage and visual security
- A basking area around 28–30°C
- A cool area around 20–23°C
- Night temperatures around 18–21°C
- Appropriate linear UVB
- Bright but heavily structured daytime lighting
- Approximately 70–90% humidity with natural fluctuations
- Excellent ventilation
- Regular misting
- Permanent access to clean water
- A varied gut-loaded invertebrate diet
- Appropriate calcium supplementation
- Minimal unnecessary handling
- Preference for captive-bred animals
When provided with moderate temperatures, dense vegetation, excellent hydration and a carefully designed arboreal environment, captive-bred Mountain Horned Dragons can make outstanding naturalistic display reptiles.
IMPORTANT INFORMATION:
This care sheet provides general husbandry guidance and does not replace species-specific research or veterinary advice. Individual requirements may vary.
Always check current legislation governing the acquisition, collection, import, transport, keeping, breeding or sale of reptiles in your jurisdiction.
If you have concerns about an animal’s health or care, consult a suitably experienced exotic or reptile veterinarian.
Information correct at the date of publication.
reptilecommunity.com | Revised: August 2026