They swim or crawl like moving there body back and forth
they use there tails
Echidnas breathe using lungs, the same as other mammals.
by using their legs
they move like any other animals and on four legs
Its uses its webbed feet to push its self through the water.
Bipedal animals have two legs - like humans. They move by walking.
they move there legs
Be more specific. Crabs have shells and they use their legs.
Frogs do not have tails when they grow up, but they can swim in water. When in water, they can swim using their webbed feet and hind legs.
Water beetles move through the water by thrusting their legs back and forth. This allows them to quickly move and catch prey.
Rhinos are four-legged animals. They move like most other such animals: by using the power of their legs. They are large, so movement is not easy for them, but they can move rapidly if they need to.
Bilbies move on land on their four legs. Their hind legs are longer, so they have a "hopping" motion when they walk or run. They are entirely terrestrial, so they do not move in water (except during floods).
It didn't. The ozone layer permitted plants and animals to move from the deep water to the water's surface, and eventually to land.