Pristimantis mutabilis, also known as mutable rainfrog, is a species of frog found in the Ecuadoran Andes in the Pichincha and Imbabura Provinces. Pristimantis mutabilis is the first known amphibian species that is able to change skin texture from tuberculate to almost smooth in a few minutes, an extreme example of phenotypic plasticity. The specific epithet mutabilis (changeable) refers to this ability. The physiological mechanism behind the skin texture change remains unknown.