Tadpole develops into an adult frog by the process of
Metamorphosis
B - Metamorphosis
During a frog's metamorphosis, an egg will hatch into a tadpole, which will then develop back legs first, then front legs, and become a full grown adult frog! Check out the process below about how a frog develops during its life. Frogs lay fertilized eggs. That's where new frogs come from.