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Squamata · AgamidaeEntry 8,828 of 21,572
Giant Forest Dragon, Gonocephalus grandis

Reptilia · Squamata

Gonocephalus grandisGray, 1845

Giant Forest Dragon

Photograph by Bernard DUPONT from FRANCE, CC BY-SA, via Wikimedia Commons

A day-active, meat-eating lizard from the Oriental region, reaching 160 mm snout to vent.

Also called Great Anglehead Lizard.

ReptiliaSquamataAgamidaeGonocephalus

Grows to
160mm
greatest recorded
Eats
Carnivorous
Active
Diurnal
Lives
Arboreal, saxicolous, terrestrial
Body length across Agamidae

Longer than 90% of all agamids anyone has measured.

90% of 583 species are smaller10% larger
32 mmthe whole family, smallest to largest418 mm

The bar is the rank itself: its length is the share of the family this animal exceeds. The chart below is the family’s real spread, on a logarithmic scale because body length here runs from 32 to 418 mm. The solid rule is this animal. Every bar is a count of real species, and nothing on this figure is estimated.

What is known

34 sourced facts, each taken from a named scientific dataset. How to read these.

Cited from a dataset unless a row is marked otherwise.

Standing in the world

Still living
Extant
Conservation status
Least Concern
Status assessed · the year the Red List last looked
2018
Population trend
Stable

The animal itself

Limbs
Four legs
Venomous
No
Fangs
None

Size

Length snout to vent · greatest recorded
160mm6.25 in

max 160 mm SVL (Feldman et al. 2016)

Length snout to vent · adult female mean
120.7mm4.75 in
Largest female · snout to vent
131mm5.25 in

snout-vent length; the source column mixes this with straight carapace length

Hatchling length · snout to vent
33.5mm1.25 in
Body mass · greatestcomputed
143.8g5.1 oz

computed from length by a family-level allometric equation, not weighed

How it lives

Diet
Carnivorous

Arthropods (e.g., Grismer 2011, Teynie and David 2010)

Active
Diurnal

e.g., Hong et al. 2021, Jenssen and Sy 2022

Where it lives
Arboreal, saxicolous, terrestrial

Arboreal, females and juveniles also terrestrial and saxicolous, escape into water (Grismer 2011), arboreal (Gray et al. 2019, Hong et al. 2021, Jenssen and Sy 2022), good swimmer (Jenssen and Sy 2022)

Habitat
Forest
Biome
Tropical & Subtropical Moist Broadleaf Forests
Active season · months of the year
12months
Region
Oriental
Mainland or island
Mainland
Highest it lives · above sea level
1400m

from <150 to 1400 (Shahriza 2018), below 1400 (Jenssen and Sy 2022)

Range size
1,315,206km²

Breeding

Reproduction
Oviparous
Average clutch
3.59eggs
Eggs or young per clutch
1–6eggs

2-5, usually 3 (Grismer 2011), 1-6, mean 3.67 (Goldberg and Grismer 2014), up to 6 (Chan-ard et al. 2015, Jenssen and Sy 2022), mean 4 (Decena et al. 2022)

Mean clutch
3.5–3.67eggs
Clutches a year
4–10per year

Naming and history

Suborder
Sauria
Infraorder
Acrodontia
Subspecies
No
Described by
Gray
Moved to another genus · since it was first described
Yes
Described in
1845
Type locality
Burma

Keeping one

2 ft 1 in × 2 ft 1 in × 2 ft 1 in(64 × 64 × 64 cm)

Minimum length × width × height, for one animal. Bigger is always better.

The standard sizes ground species at 4 × 4 × 2.5 and climbing species at 4 × 2.5 × 4 times snout-vent length.

Recorded both on the ground and climbing, so this is the larger of the two rules in every dimension.

Lives on rock, so stable hard surfaces and basking ledges suit it.

Mindestanforderungen an die Haltung von Reptilien (Sachverständigengutachten), German Federal Ministry for Nutrition, Agriculture and Forestry, Animal Welfare Division, 10 January 1997. The standard states these floor areas are recommendations rather than binding limits.

From this animal’s own snout-vent length of 6.25 in (160 mm), at 4 × 4 × 4 times it, following the German federal welfare standard — how this is worked out.

No preferred body temperature has been recorded for Giant Forest Dragon. Rather than repeat a number from a care sheet, this page leaves it out.

Feeding

A prey item should be no wider than the space between the animal's eyes.

Widely used across reptile husbandry references. The stated reason is that the gap approximates the width of the throat, so wider prey is associated with impaction. This is established practice, not a measurement.

16kJ per day

Worked out for an animal of 144 g, the heaviest recorded for Giant Forest Dragon — so it is the top of the range, not a figure for a particular animal. Weigh yours and the number will be lower.

An upper estimate, not a feeding target, and not veterinary advice. The equation covers only what an animal burns staying alive, so a growing, gravid or recovering animal needs more — and it was measured on wild animals, which move far more than one in an enclosure. Body condition and a vet who knows the species are what a feeding decision should rest on. Where this comes from.

What nobody knows

These are not gaps in our research. No scientific dataset records them for this species — and saying so is information you cannot get from a reference that simply leaves a field out.

  • Length snout to vent · adult male mean
  • Length snout to vent · adult mean
  • Length nose to tail · greatest recorded
  • Female length · mean, nose to tail
  • Length nose to tail · adult male mean
  • Length nose to tail · adult mean
  • Largest male · snout to vent
  • Largest female · shell length
  • Largest male · shell length
  • Hatchling length · nose to tail
  • Largest juvenile · snout to vent
  • Largest juvenile · shell length
  • Egg length
  • Egg width
  • Body mass · a typical adult
  • Body mass · adult female, mean
  • Body mass at hatching
  • Longest recorded life
  • Preferred body temperature · chosen in a laboratory gradient
  • Body temperature when active · measured in the wild
  • Eats arthropods
  • Eats vertebrates
  • Eats plant matter
  • How it hunts
  • How the young develop
  • Gestation or incubation
  • Clutches in a year
  • First breeds from · youngest recorded
  • First breeds by · oldest recorded
  • Hatchling length · smallest recorded
  • Hatchling length · largest recorded
  • Age at first breeding · female
  • Mature from · youngest recorded
  • Mature by · oldest recorded
  • Size at maturity · smallest recorded
  • Size at maturity · largest recorded
  • Body temp in the wild · lowest mean recorded
  • Body temp in the wild · highest mean recorded
  • Colour on the back
  • Pattern on the back
  • Pupil
  • Sex decided by
  • Red List criteria
  • Density · lowest recorded
  • Density · highest recorded
  • Home range · largest recorded
  • Active in
  • Lowest it lives · above sea level

Others in Agamidae

Take this data

Everything on this page is available as data under CC BY 4.0 — use it freely, credit it, no permission needed.

This species as JSON · the whole dataset

Cite this page

The Reptile & Amphibian Encyclopedia (2026). Gonocephalus grandis. Retrieved 2026-09-08, from https://www.allanglescreatures.com/species/gonocephalus-grandis

@misc{gonocephalus_grandis_2026,
  title  = {Gonocephalus grandis},
  author = {{The Reptile & Amphibian Encyclopedia}},
  year   = {2026},
  url    = {https://www.allanglescreatures.com/species/gonocephalus-grandis}
}

Sources

  1. Meiri, S. (2024). SquamBase — a database of squamate (Reptilia: Squamata) traits. Global Ecology and Biogeography. Public domain (CC0).
  2. Oskyrko, O. et al. (2024). ReptTraits: a comprehensive dataset of ecological traits in reptiles. Scientific Data. Used under CC BY 4.0.
  3. Catalogue of Life (dataset 3LR), used under CC BY.