Abstract
A curiously short and squat snake has long been reported in the Japanese archipelago. Frequently said to occur in mountainous areas in the center of the archipelago, this reptile has been given as many as 40 different local names. We have retained here the name tzuchinoko, which is the most frequently used. Reported descriptions indicate that it is very probably a crotalid snake belonging either to the common species Agkistrodon halys (representing abnormal individuals, unusual behavior, or confused interpretations of observations), or to a yet unidentified species.