An Angiak is a child of the living dead. During harsh times, the Eskimos often had to give up their children, so they did this by abandoning them in the snow.
If the Eskimos don't leave the land on which they gave up their child, it is said that their deceased child's vengeful spirit would find its original body and reanimate it, so their appearance seems vampiric like. The Angiak would then return to the tribe to haunt the Eskimos and each visit back to the tribe would strengthen the Angiak because it would feed upon the mothers breast during the nighttime until it had enough strength to shapeshift into animals and eventually kill each member oof the Eskimo tribe, one by one.