This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Ishigaq (Inuit)
Ishigaq - this how Inuit call “little people,” who live across the entire Arctic territory in caves, mountains, or underground. The word itself means "those who hide." These strong, fast and very intelligent creatures, extremely skilled in hunting, wear clothes made of animal skins and live their own separate lives. Ishigaq are considered good folk and can lead lost hunters or children to their house, but there are other, more vicious and even dangerous.
Kallak and his daughter produced the race of giants who warred with Sila and were killed by him in the end. Nunam brought the slain giants (who are her brothers, not her children in some versions) back to life. Sila insisted they be punished however, and shrunk the giants, who became the Ishigaq, the one meter tall Inuit version of elves.