Axolotl An aquatic salamander from Mexico. As an adult it retains many larval features, such as its feathery gills.

Bullfrog A very large frog. It grows up to 25 centimetres (10 inches) long and eats almost anything, including birds and mice. It is known for its booming mating call.

Caecilian A long, snake-like amphibian with no limbs. Caecilians have small, almost sightless, eyes and live underground in tropical regions.

Congo eel A North American salamander with a long thin body and four tiny, useless legs. It lives at the bottom of streams, feeding on frogs, fish and snakes.

Darwin’s frog A small South American frog with a pointed snout. It stores its eggs in a sac of skin in its throat until they mature and jump out as miniature adults.

Fire-bellied toad An Asian toad with a brightly coloured belly. If threatened, it twists to show its belly as a warning that it tastes bad. This action, called the unken reflex, is also used by some salamanders.

Fire salamander A European salamander with black and yellow markings. It lives in cool forests or mountainous regions.

Flying frog A frog with large, webbed feet that help it glide between trees. Some species can glide more than 15 metres (50 feet).

Frog A short, tail-less amphibian with long hind legs and smooth skin. Frogs live on land, in trees or in fresh water. They can make huge leaps and swim quickly.

Gills The breathing organs of water creatures. As water passes in through the mouth and out over the gills, oxygen is filtered out by blood vessels. Amphibian larvae have feathery or flap-like gills.

Japanese giant salamander One of the world’s largest amphibians. It can grow to lengths of up to 1.5 metres (5 feet). It lives in streams where water supports the great weight of its body. The Japanese giant salamander snaps up fish and worms with its large, gaping mouth.

Larva The young of an animal before it goes through metamorphosis. Larvae look very different to adults of the same species. For example, the larvae of many amphibians have gills or tails, which are lost when they become adults.

Metamorphosis The process whereby some animals change their bodies and behaviour between the young (larval) and adult states of their life.

Midwife toad A dull-coloured toad from Europe. The male wraps the female’s eggs around his legs to protect them until they are ready to hatch.

Mole salamander A thick-bodied, colourful North American salamander with colourful markings. Adults live in burrows, returning to the water only to lay their eggs.

Mudpuppy An aquatic North American salamander that keeps its gills as an adult. Mudpuppies are also known as waterdogs because adults have a “barking” call.

Newt A type of salamander with a long, flattened tail. Many species of newts are brightly coloured to warn that they are toxic.

Olm A large, aquatic salamander that lives in European caves. An olm has pale skin, blind eyes and feathery external gills.

Poison dart frog A frog from the rainforests of Central and South America that secretes a powerful poison. This is used by rainforest people to coat the tips of their darts and arrows for hunting.

Salamander An amphibian with a long body and tail. Some salamanders are fully aquatic, while others live on land and return to the water only to lay their eggs.

Siren An aquatic salamander with small front legs and no back legs.

Spawn The jelly-like eggs of aquatic animals, such as frogs and toads. Many frogs and toads leave their eggs to hatch on their own. Others carry them on their backs or legs, or in their mouths, to protect them.

Tadpole The young of a frog or toad. At first, tadpoles breathe through gills and use their tails to swim. Gradually, their legs emerge, they develop lungs and finally they lose their tails.

Toad A short, tail-less amphibian with a fat body and lumpy skin. Toads live mostly on land. They have shorter legs than frogs and crawl or hop rather than leap.

Tree frog A frog that lives and hunts in trees using its sticky toe pads to give it grip. Most species leave the trees to lay their eggs in pools or rivers, but some lay their eggs on leaves overhanging water.

Vocal sac An inflatable bag of skin that male frogs use to amplify their calls. Calls are used to attract mates or ward off rivals.

Consultant: Chris Jarvis