Tsuchinoko

Description
A tsuchinoko (also known as the bachi hebi) is a snakelike youkai that is endemic to Japan. The largest tsuchinoko are about 85 centimeters long, and at the middle of their body, they are thicker than they are long. They possess venomous fangs and a muscular body, and tend to move either by slithering or by curling up and springing meters at a time. Some tsuchinoko are supposedly able to also curl up into hoop shapes, taking their tail in their mouth and rolling to get about.

Not all tsuchinoko are sentient, but the intelligent ones are very prone to lying. Either way, they are very fond of sake and other alcoholic drinks, and are easily placated with offering of such a thing.

Origin
As a manner of snake youkai, the tsuchinoko probably originated from rumors, folk-tales and odd beliefs about wild snakes. They are particularly rare in the Outside World, and have been so for a very long time, to the point of humans considering them a type of cryptid.

Because of their occasional habit to roll about in a hoop shape, they may have some connection to supernatural snake species from other regions as well.