This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Indus Worm (Medieval Bestiaries)
The Indus worm or the horrible Indian worm, in ancient Greek writings, was a supposed giant, white, carnivorous worm with a large pair of teeth that lived in the Indus River. Ctesias's Indica described the worm or as the only creature to inhabit the Indus. It resembled the worm which infested figs, but averaged 7 cubits (10 ft) in length. It had a pair of large teeth, one on the upper jaw and one on the lower.
The teeth were square, measuring 1 pyg?n in the Ancient Greek scale of length, about 15 inches long. It burrowed in the mud bottom by day, and nocturnally devoured prey such as horses, cows, donkeys or camels. Philostratus, reporting on the creature of the same river system, said it resembled a white worm, alluding to its color.