There are more than 11,000 species of reptiles on the planet, and they can be found on every continent except Antarctica.

Contrary to popular belief, a chameleon changing its skin color doesn't necessarily mean the animal is trying to camouflage itself. More often, this remarkable ability is used as a way of controlling body temperature--lightening skin to reflect light and cool down or darkening skin to absorb light and warm up. Another primary function of color change is social signaling: altering skin tone to communicate intentions to potential mates or rivals.

A tortoise is land-dwelling, while many (though not all) other turtle species are at least partly aquatic.

Crocodiles have a very slow metabolism, which allows them to survive long periods without food. In fact, larger crocodiles can go for over a year without eating a meal.

Tuatara are sometimes referred to as "living fossils" because they are the only surviving member of the order Rhynchocephalia, which originated in the Triassic period around 250 million years ago. They are also unusual in having a pronounced photoreceptive eye, the third eye, which is thought to be involved in setting circadian and seasonal cycles. They are able to hear, although no external ear is present, and have unique features in their skeleton, some of them apparently evolutionarily retained from fish.

The death adder can attack, inject venom, and go back to striking position in less than 0.15 seconds.

Turtles appear to have lost their teeth about 150-200 million years ago. Their upper and lower jaws are instead covered by horny ridges. Carnivorous turtles usually have knife-sharp ridges for slicing through their prey. Herbivorous turtles have serrated-edged ridges that help them cut through tough plants. They use their tongues to swallow food, but unlike most reptiles, they cannot stick their tongues out to catch food.

Chameleon saliva was found to have an average viscosity of 0.4 pascal-seconds, making it about 400 times thicker than human saliva. This sticky spit helps the chameleon capture prey weighing up to 30% of its body weight using only its tongue.

The plumed basilisk (Basiliscus plumifrons) has an amazing ability to run on water. To accomplish this, it uses long toes on its rear feet with fringes of skin that unfurl in the water, increasing surface area to keep it from sinking, provided the lizard can maintain enough speed. In Costa Rica, this has earned the plumed basilisk the nickname "Jesus Christ lizard."

Unlike other turtles, sea turtles cannot retract their flippers and head into their shells. But their streamlined shells and large paddle-shaped flippers make them very agile and graceful swimmers.