A mom saw her children gazing at a little cluster of round balls. They looked clear with a black dot in them, and the mother thought they were rather odd looking. She had no idea what they were, but the kids were quick to step in and educate her: they were frog eggs.
Frogs are amphibians and, thus, egg-laying creatures. If you're lucky, when you're by some water during the breeding season, you might find a clump of 'frog spawn' or eggs. Frog eggs look like little balls of clear jelly with a tiny, black dot in the center. These dots are the future frogs. Once they get bigger and start wiggling, they are probably getting ready to hatch.
The word 'amphibian' means 'two lives', which makes sense if you think about the life cycle of a frog. When frogs are first hatched from their eggs, they're born in water. For its first few weeks, that's where they stay. Their tiny bodies are more like a fish. They have no arms or legs, they have a long tail and gills.
In time, though, they'll grow arms and legs and lose their tail. They'll climb out on land and become a frog. They'll swim once in a while, but will mostly live on land for the rest of its life. It's like being reborn in a whole different body.
At that point, the frog looks to mate, and it starts the entire cycle over again.