A tiny amphibian with a superpower straight out of science fiction — it can change the texture of its skin in just a few minutes, switching from smooth to spiny and back again. Discovered in the cloud forests of Ecuador and formally described in 2015, this fascinating frog belongs to the incredibly diverse Pristimantis genus, known for its terrestrial, direct-developing species. But P. mutabilis stands out from its relatives thanks to its unique ability to literally morph its appearance.

This unusual ability earned it the nickname “shape-shifting frog”, and it was the first vertebrate ever documented to rapidly alter its skin texture in this way. Scientists first noticed this bizarre trait when a frog captured in the field looked smooth in a photograph — but developed bumpy, spiny skin while in captivity. When researchers placed it back on mossy textures, it returned to its smoother form in just minutes. The function of this texture change is believed to be camouflage, allowing the frog to better blend in with different surroundings such as moss, lichen, or smooth leaves.

Despite its dramatic talent, the mutable rainfrog is very small, measuring only about 2–3 cm (under 1.5 inches). Its colors are subtle — typically brown or greenish with speckles — which makes it easy to overlook in the forest understory. It lives in high-elevation cloud forests, around 1,800–2,000 meters above sea level, where mist, moss, and ferns dominate the landscape.

Like other Pristimantis species, the mutable rainfrog doesn’t have a tadpole stage. Its eggs hatch directly into miniature frogs, which allows it to live away from water and survive in leaf litter and tree hollows. It is mostly nocturnal, coming out at night to hunt for small insects and arthropods among the forest floor and vegetation.

Distribution

Country

Population est.

Status

Year

Comments

Ecuador

EN

2021