Pseudis paradoxa

Pseudis paradoxa, known as the paradoxical frog or shrinking frog, is a species of hylid frog from South America. Its name refers to the very large—up to 27 cm (11 in) long—tadpole (the world's longest), which in turn "shrinks" during metamorphosis into an ordinary-sized frog, only about a quarter or third of its former length. Although the recordholder was a tadpole in Amapá that belonged to this species, others in the genus Pseudis also have large tadpoles and ordinary-sized adults.