From Wikipedia: In practice the Hamatsa initiate, almost always a young man at approximately age 25, is abducted by members of the Hamatsa society and kept in the forest in a secret location where he is instructed in the mysteries of the society. Then at a winter dance festival to which many clans and neighboring tribes are invited the spirit of the man-eating giant is evoked and the initiate is brought in wearing spruce bows and gnashing his teeth and even biting members of the audience. Many dances ensue, as the tale of Baxbaxwalanuksiwe is recounted, and all of the giant man-eating birds dance around the fire.
Finally the society members succeed in taming the new “cannibal” initiate. In the process of the ceremonies what seems to be human flesh is eaten by the initiates. Boas describes the hamatsa initiate as eating actual human flesh without chewing. After the ceremony, the initiate is forced to drink large amounts of sea water to induce vomiting, thereby voiding the body of potentially harmful toxins. All persons who were bitten during the proceedings are given expensive presents, and many gifts are given to all of the witnesses who are required to recall through their gifts the honors bestowed on the new initiate and recognize his station within the spiritual community of the clan and tribe.
Common knowledge about squirrels is that they are basically furry rats. Yes, they are adorable in an amnesiac sort of way, what with their inability to remember where they buried their nuts, but the modern squirrel is not typically considered a manifestation of anything monstrous. Interestingly, much like Coca-Cola and Pop Rocks, if you combine Viking aesthetics with squirrels, you produce a malevolent little rodent called Ratatoskr (“Drill Tooth” in Old Norse) that spends his days spreading malicious gossip and trying to start a fight between the eagle at the top of the World Tree Yggdrasil and the angry Wyrm beneath called Níðhöggr, generally with phrases like, “Did you hear what he said about your mother?”