This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Hoop Snake (United States, Canada, and Australia)
The hoop snake is a legendary creature of the United States, Canada, and Australia. It appears in the Pecos Bill stories; although his description of hoop snakes is the one with which people are most familiar, stories of the creature predate those fictional tales considerably. Several sightings of the hoop snake have been alleged along the Minnesota-Wisconsin border in the St. Croix River valley.
According to folklore, the distinguishing feature of a hoop snake is that it can grasp its tail in its jaws and roll after its prey like a wheel. In one version of the myth, the snake straightens out at the last second, skewering its victim with its venomous tail. The only escape is to hide behind a tree, which receives the deadly blow instead and promptly dies from the poison.