The frilled dragon can grow to nearly 3 feet in length and is typically a mixture of brown and gray. However, depending on their environment, their coloration can be orange or green. 

The frilled dragons are named after their distinguishing neck frill that surrounds their head. The frill can be as wide as the lizard is long when they reach full maturity. When frightened or agitated, it expands its frill up to a foot wide to ward off predators or to establish dominance over other frilled dragons in a territorial dispute. If that dramatic display does not work, the lizard tends to flee up the tree closest to them to escape.

They are able to expand their frills thanks to possessing two long and rod-like bones called hyoids. These hyoids have muscles connected to them and once the frilled dragon, flexes them the fills expand. However, this also causes them to open their mouth while they are expanding.

Frilled dragons mainly eat insects and vertebrates, including smaller lizards. They are ambush predators and eat an extremely large amount of food when in their “binge periods” of the rainy seasons.

The color of their frills typically varies from red, orange, yellow and white and has been shown to change based on their diet. According to research published by Australian National University some insects, if consumed on a regular basis, contain pigments that can alter the shade of the frilled dragon’s frills and turn them darker in color over time.

Frilled dragons find their mates through intrasexual selection, meaning that the males of the species fight each other for mates in addition to showing off their impressive neck frills. Female lizards typically lay their eggs between the months of November to February and will bury them 1-8 inches below ground. The female will lay 1-2 clutches of eggs with each clutch containing 6-25 eggs. After 2 to 3 months, the offspring hatch. 

The temperature of the frilled dragon’s nest can help determine if their babies will be male or female. Studies have shown that eggs kept around 79°F yield mostly females, while those kept around 84°F produce an even split between males and females. Biologists call this “temperature-dependent sex determination”, or TSD.

Frilled dragons have been given the nickname “bicycle lizard” because they raise up on their hind legs and wheel them in wide circular motions while running.