Giant plated lizards are large and are characterised by a flattened head and body profile. There are known to grow up to 690 mm in total body length. The back of the lizard is dark brown to black, with each head shield and dorsal scale spotted yellow, giving a speckled appearance; a pair of broad stripes is sometimes present along the back. The throat is dirty white, and the belly is light brown. During the breeding season, the chin, throat and sides of the head of the males become tinged with pink-purple. The giant plated lizard has an omnivorous diet of leaves, flowers and fruits, as well as insects, spiders, millipedes, scorpions and the occasional small lizards and baby tortoises. Giant plated lizards can live for eight to seventeen years in captivity.