This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Gyascutus (American folklore)
Gyascutus, an imaginary, large, four-legged beast with legs on one side longer than those on the other, for walking on hillsides. Humorous references to this creature, whose name has countless local variants, first appeared in American newspapers during the 1840s. It has continued to play a minor role in American folklore since then.
Of course the animal was highly susceptible to calamity if it got turned around with its longer legs on the uphill side of the mountain. The result was that he would usually tumble to the bottom of the mountain and die. Little is known about the appearance of this creature. All sources agree that the it is herbivorous and quite timid. Some say it's badger-like. Some say it's goat-like.