Chameleons do not have external ears or a tympanic membrane, but they do have internal ears as well as degenerated middle ears. They do not hear well but they can detect low frequency sounds.
The horns on a chameleon are made up of ringlike segments of inner bone covered by a hard keratin-like skin.
Chameleons can project their tongue up to 2.2 times their body length.
Some chameleons play dead to avoid predation; this is called thanatosis.
Chameleons change color by rearranging a lattice of nanocrystals in one of their top layers of skin cells called iridophores. Chameleons can then stretch this layer, broadening the nanocrystalline lattice, thereby causing it to reflect a different wavelength of light.
The word Brookesia is named after the British naturalist Joshua Brookes.
The chameleon tongue accelerates towards its target at over 1642m per second. Chameleons rarely miss their intended food item.
Chameleons have laterally compressed bodies. This enables them to warm up quickly by presenting a larger surface area to the sun. It also helps some chameleon species blend in among the similarly shaped leaves in their environment.
Pygmy chameleons (Brookesia, Palleon, Rhampholeon and Rieppeleon sp.) often resemble dry leaves, mosses and branches.
The word Chamaeleo is derived via Latin from the Greek word khamaileon. It roughly translates to ground lion. Khamai means on the ground and leon means lion.