Its common names refer to the large frill around its neck, which usually stays folded against the lizard's body.

The frilled lizard grows to 90 cm (35 in) from head to tail tip and can weigh 600 g (1.3 lb).

[3] British zoologist John Edward Gray described the frilled lizard in 1825 as Clamydosaurus kingii.

He used a specimen collected by botanist Allan Cunningham at Careening Bay, off north-western Australia, while part of an expedition conducted by Captain Phillip Parker King in HMS Mermaid.

It split from its closest living relatives around 10 million years ago based on genetic evidence.

[9] A 2017 mitochondrial DNA analysis of the species across its range revealed three lineages demarcated by the Ord River and the southeast corner of the Gulf of Carpentaria (Carpentarian Gap).

Frilled lizards entered southern New Guinea possibly around 17,000 years ago during a glacial cycle, when sea levels were lower and a land bridge connected the island to Cape York.

[11] Frilled lizard (Clamydosaurus kingi) Gilbert's lashtail (Lophognathus gilberti) Jacky dragon (Amphibolurus muricatus) Mallee heath dragon (Amphibolurus norrisi) The frilled lizard grows to a total length of around 90 centimetres (35 in) and a head-body length of 27 cm (11 in), and weighs up to 600 g (1.3 lb).

[8][12][14] The species is sexually dimorphic, males being larger than females[10][12] and having proportionally bigger frills, heads and jaws.

[15] The corners of the frilled lizard's eyes are pointed and the rounded nostrils face away from each other and angle downwards.

When fully extended, the frill is disc-shaped and can reach over four times the length of the animal's torso in diameter, or around 30 cm (12 in) across.

[3] Frilled lizards vary between grey, brown, orangish-brown, and black dorsally, the underside being paler white or yellow.

The underside and lateral sides of the species are sprinkled with dark brown markings that merge to create bands on the tail.

Its Australian range stretches from the Kimberley region of Western Australia east through the Top End of the Northern Territory to Queensland's Cape York Peninsula and nearby islands of Muralug, Badu, and Moa, and south to Brisbane.

[23] Frilled lizards do not enter torpidity during the dry season, but they can greatly reduce their energy usage and metabolic rate in response to less food and water.

[21] This species is a sit-and-wait predator: it watches for potential prey from a tree and, upon seeing it, climbs down and rushes towards it on two legs before descending on all four to grab and eat it.

[22] The International Union for Conservation of Nature lists the frilled lizard as of least concern, due to its abundance and wide range, but warns that its population may be locally declining in some areas.

Frilled lizards may also be threatened by feral cats,[1] though they do not appear to be significantly affected by the invasive cane toad.

[12] Archaeological evidence indicates that frilled lizards were eaten by some indigenous peoples in ancient times.

[36] In the late 19th century, William Saville-Kent brought a live lizard to England where it was observed by fellow biologists.

In Steven Spielberg's 1993 film Jurassic Park, the dinosaur Dilophosaurus was portrayed with a similar neck frill that rose when attacking.