What is the common name of the frog whose tadpole is larger than the adult?

The frog whose tadpole is larger than the adult is the paradoxical frog.

The paradoxical frog, Pseudis paradoxa, is also called the shrinking frog because its extraordinary tadpole becomes dramatically smaller during metamorphosis. Tadpoles can grow to roughly three or four times the adult frog’s length, with some reported specimens reaching about 27 centimetres. After developing legs and absorbing the tail, the animal emerges as an adult only around 4.5–7.5 centimetres long.

This unusual life cycle is not a trick or a case of the frog shrinking after adulthood. The tadpole itself is the growing larval stage, and metamorphosis restructures its body into a much more compact adult form. Tadpole size varies with food, water conditions, and predator pressure.

Paradoxical frogs inhabit ponds, lakes, lagoons, and slow waters across parts of South America, including the Amazon and Guianas. Their tadpoles feed mainly on algae, while adults eat insects and other invertebrates and may even capture small frogs. The name “paradoxical” refers specifically to the striking size relationship between larva and adult.