Ithaqua the Wind Walker
Ithaqua the Wind-Walker is the Lovecraftian version of the wendigo. Ithaqua was created by August Derleth for his short story "Ithaqua" in 1941, a story which borrowed heavily from Algernon Blackwood's 1910 "Wendigo" short story. As such, Ithaqua is one of the Cthulhu Mythos horrors which bears a most striking resemblance to real-world occult lore. The wendigo was a part of North American native lore going back centuries.
Description of Ithaqua
Nevertheless, August Derleth's Ithaqua is described much more in keeping with the cosmic horrors of H.P. Lovecraft than any beast from Native American or First Nations mythology. This is how August Derleth described the creature in "The Thing That Walked on the Wind":
"The stars had been blotted out...the great cloud which had obscured the sky looked curiously like the outline of a great man. And...where the top of the 'cloud' must have been, where the thing should have been, there were two gleaming stars, visible despite the shadow, two gleaming stars, burning bright--like eyes!"
Indian Depictions of Wendigo
In Native American lore, the wendigo is a monster which combines traits of a vampire and (perhaps) even a werewolf. The wendigo was closely tied to the breaking of one of humanity's great taboos: cannibalism. According to Indian myth, humans that engaged in cannibalism would transform into the wendigo. Since they became supernatural creatures which hunted human flesh and since they had the ability to appear (seemingly) out of nowhere, wind-walkers have definite traits of the European vampire. The wendigo appeared as a clearly inhuman monster to its victims, though, which is why I make the comparison to the werewolf.
Algonquin-speaking Indian tribes of the Northern United State and (especially) First Nations tribes of Canada like the Ojibwe and the Cree long had tales of the wendigo. In fact, it appears that a "wendigo psychosis" was a psychological condition which afflicted some North American natives of the past, where they craved human flesh, but feared the act would transform them into a horrible monster. It should be noted these stories came out of a culture associated with the extreme north with harsh winters that were prone to famine and starvation in winter, so a strong taboo might have instituted to prevent outbreaks of cannibalism. The idea was a cannibal could never stop: once they had a taste for flesh, that craving became immoderate and supernatural. The obvious implication was starving humans should choose resignation to death or suicide instead of cannibalism.
The typical wendigo, once transformed, became a manitou or spirit. This being was invisible to its victims until it was too late, though the victim might have some inkling they were being watched. The wendigo would walk on the wind and stalk its newest prey, but was in all cases beyond human. In some tribes, lore speaks of rituals that would allow one to become a wendigo (through black magic). In other tribes, those Indians guilty of extreme greed became wendigo. Modern arcane lore and pop culture has turned the wendigo into a creature much like the vampire, the werewolf, or even the zombie, but the original was an elemental creature--which may explain the attraction to August Derleth. Ithaqua, the Cthulhu Mythos version of the wendigo, was a much different creature from all.
Ithaqua's Cult
In the Cthulhu Mythos, Ithaqua was first encountered by the Native Americans. Ithaqua was the source of the wendigo legends and possibly even the stories of the sasquatch. Those who travel in the far north are hunted and devoured by him. While he has only a small cult, the inhabitants of Siberia and the Arctic region of North America leave sacrifices to appease him. Those who do become members of Ithaqua's cult are not susceptible to the cold.
Races Associated with Ithaqua
Ithaqua's typical servitors are the Shantaks--slimy bird-creatures with bat wings that are described as larger than elephants. According to their first description by Randall Carter in H.P. Lovecraft's The Dream-Quest of Unknown Kadath, Shantaks live in the Dreamlands, are hunted by Nodens, and greatly fear the Nightgaunts.
The Gnophkehs, a race of cannibals, are said to worship Ithaqua, though the Gnophkehs also worship Aphoom-Zham and Rhan-Tegoth.
Ithaqua in the Titus Crow Series
In Brian's Lumley Titus Crow series, Ithaqua appears a prominent figure in the otherdimensional ice-world known as Borea. According to Lumley, Ithaqua travels "the winds of space" between Borea and Earth in order to bring back victims to worship him in the arctic wastes of Borea. The female humanoids among these victims are often the target of his attempts to reproduce. Ithaqua's reasons for doing this are mysterious, but it might be an experiment to create offspring who can transcend the limitations imposed on him by the Elder Gods which keep him bound to Borea. Alternately, he might simply want offspring out of a sense of loneliness, since he's the only one of his race. If so, all of his attempts towards this end are thwarted, because all of his spawn have turned against him in the past.