The genus containing the olm, a cave-dwelling aquatic salamander, is Proteus.
The olm is formally Proteus anguinus, and it is the only living species in its genus. It belongs to the family Proteidae, whose other extant genus is Necturus, the mudpuppies and waterdogs of North America. Unlike many salamanders, the olm spends its entire life underwater.
Olms inhabit submerged cave systems in the Dinaric Alps, especially in Slovenia, Croatia, Bosnia and Herzegovina, and the area near Trieste in Italy. Their pale skin, reduced eyes, and elongated bodies reflect life in perpetual darkness. They can detect chemical, mechanical, and electrical signals, helping them locate prey when vision is of little use.
The name Proteus also creates a common mix-up: it is shared with Proteus, a genus of bacteria, and with Proteus from Greek mythology, a shape-changing sea figure. The salamander's scientific name was assigned by Josephus Nicolaus Laurenti in 1768. Slovenian folklore once treated washed-out olms as baby dragons, earning them the local nickname “human fish.”