Olm

The olm is a blind, aquatic salamander native to the underground cave systems of the Dinaric Alps in southeastern Europe, adapted so completely to permanent darkness that it has become one of the best-known examples of cave-dwelling life. Its skin is pale pink to white due to a near-total lack of pigment, and its eyes are vestigial and covered by skin, rendered functionally useless, while it instead relies on a highly developed sense of smell, hearing and electroreception to navigate and hunt in the lightless water. Unusually among amphibians, the olm retains its larval, gilled form for its entire life in a condition called neoteny, never undergoing full metamorphosis into a terrestrial adult, and it breathes partly through external feathery gills as well as its skin and simple lungs. It is extraordinarily long-lived for an amphibian, with individuals estimated to survive well past a century, and it can go for years without food by drastically slowing its metabolism, sometimes even resorbing its own tissues. Confined to a fragile network of caves vulnerable to water pollution, the olm is considered vulnerable, and it holds deep cultural significance in the region, where folklore once described it as a baby dragon.