Clawed salamanders of the genus Onychodactylus are among the most interesting amphibians, not just by having claws. Unlike most other amphibians, they do not have lungs but breathe through their skin, a feature especially shared with species of the amphibian family Plethodontidae. Clawed salamanders are representatives of another family, Hynobiidae, which is considered to have the most primitive characteristics among all the recent, tailed amphibians. However, both evolutionary derived features and characteristics even more primitive than in other hynobiids are combined in their morphology. The geographical distribution of the clawed salamanders is limited to a few mountain systems in the continental Far East and Japan. This is related to their pronounced environmental requirements; clear and cool mountain upstreams, high air humidity, and mild winters are all necessary. Although the clawed salamanders have been known to scientists for more than 200 years, many aspects of their life remain an enigma. Additionally, because of peculiarities of their distribution, most of the data have been published in Japanese, Russian, Chinese and Korean, thus have remained almost unavailable to Western readers. This book aims to present an overview of all available information. It is intended not only for professional herpetologists, but everybody interested in the nature of the Far East, as well as professional and amateur amphibian keepers.