Species: olm
The olm (Proteus anguinus) is a water-dwelling salamander native to caves in the Dinaric Alps of southern and southeastern Europe. Unlike most amphibians, they live entirely within water, never coming out on land when they become adults. They are the only exclusively cave-dwelling species with a backbone native to Europe, and have a number of adaptations to their underground lifestyle such as blind, undeveloped eyes and highly acute senses of smell and hearing. They are classified as Vulnerable on the IUCN Red List of Threatened Species.