JinShin-Mushi is a (Japanese) Beetle known as the Earthquake beetle.
Although its called a beetle, it has the head of a Dragon, Spider like legs and a scaly body. Its little nickname 'Earthquake beetle' comes from the fact that is causes earthquakes by shaking it's heavy body.
(And no, I did not just make this creature up! I know you read this thinking, there is no way that is actually the name of a mythical creature! :) Same thing goes for yesterdays creature)