Fish have scales and lay eggs. But, unlike reptiles, all fish live in the water and breathe through gills. The scales of fish and reptiles look very different and are of different composition. Fish eggs are without a shell and are deposited in water. Fish are not reptiles.
Amphibians have four legs, and often look like reptiles.
But amphibians, such as salamanders and frogs, have moist skin that does not protect them from drying out, and toes without claws. The eggs of amphibians are gelatinous and have no shell. Amphibians usually go to water or very moist places to breed and lay their eggs. Amphibians are not reptiles. A few mammals lay eggs and most have claws.