This list of mythical creatures that begin with this letter and I am constantly gathering information from each continent, and is continually being updated.
Haietlik (Nuu-chah-nulth)
The haietlik is a lightning spirit and legendary creature in the mythology of the Nuu-chah-nulth (Nootka) people of the Canadian Pacific Northwest Coast. According to legend, the haietlik is both an ally and a weapon of the thunderbirds, employed by them in the hunting of whales. They are described as huge serpents with heads as sharp as a knife and tongues that shoot lightning bolts.
A blow from a haietlik injures a whale enough that the hunting thunderbird can carry it away as prey. The haietlik is variously described as dwelling among the feathers of the thunderbirds to be unleashed with a flap of the wings, or inhabiting the inland coastal waters and lakes frequented by the Nuu-chah-nulth people.