Wendigo

A Wendigo (WIN-dee-go, Eng., from Ojibwe wiindigoo "wendigo", a legendary possessing spirit) is a savage, cannibalistic Wesen that appears in. They are compulsive man-eaters, and are said to have breath like burnt flesh.

Legend
The Anishinaabe, Ojibwe, and Cree Native Americans all observed compulsive cannibalistic behavior in some individuals. It was said that if someone consumed human flesh, they risked the danger of accidentally becoming possessed by a demon, which would cause the human to take on the demon's form. The demon, known as a Wendigo, would drive the human into a compulsive cannibalism known as "Wendigo psychosis". The widespread fear of the Wendigo led to a social taboo around cannibalism.

Legend also has it that the Wendigo's hunger could never be sated. Wendigos would compulsively eat human after human, and as it consumed more, it would become larger, causing the stomach to never become full. As a result, a Wendigo that had consumed several humans in a short time would become very large.

Grimm explains that Wesen "fang out" at a certain age, so this would explain the onset of Wendigo psychosis.

Characteristics
When woged they grow short snow-white fur over their body, their teeth develop into needle-like fangs, their eyes turn yellow and appear to glow, their ears elongate, and their nails grow into long curved claws, which they often use in fights. Wendigos also have a distinctive brow ridge that curve downward in a half-U shape at the outer ends of their brows, before smoothly transitioning with the rest of their heads.

Unlike most Wesen whose voice remains unchanged or becomes deeper when they Woge, Wendigos gain a higher pitched voice.

It is unsure how strong they are, because a human, Craig, was able to handle two Wendigos (though not at once), and was even able to kill one and severely injure another (albeit with a gun) while Hank was able to handle one by himself (however it should be noted, both were big men, and thus stronger than average, as well as both being trained fighters, one a police officer, the other a soldier). Likewise a single Wendigo was able to fair quite well against a Grimm, after it had been wounded.

They are at least more durable than humans, able to run away moments after an intense fight, likewise it took several bullets from a hand gun to kill one, even at close range.

Behavior
In the distant past Wendigos were savage cave dwellers in which they carelessly stored the remains of their victims. In modern times however Wendigos have been forced to adapt, and now store the remains of past meals in pits located in the basements or crawl spaces of their homes.

Despite becoming more civilized, Wendigos are extremely savage when provoked, since one of Nick's ancestors stated that he was lucky enough to get away with his life after a direct confrontation with one. Despite this, like most Wesen, Wendigo fear Grimms, as demonstrated by John Kreski's reaction to Nick. However, they will still fight with them. It should be noted that if they get wounded they become more ferocious.

They appear to be sadistic creatures, as they enjoy mocking their prey before eating them.

Excerpt from Grimm Diaries
''Huntington, Vermont. April 5, 1759''

"After the disappearance of the magistrate and his wife, I tracked what I believed to be a Wildermann through Starksboro into the Camel's Hump forest. It was there I first heard of the mythical Wendigo from the chieftain of the Algonquian tribe that had provided me refuge for the night. 

''I soon learned that these terrifying beasts are no myth. I came upon the cave of the Wendigo, rife with human remains, having been the scene of many murders and cannibalistic acts.''

''Two days later, I encountered the Wendigo himself. His eyes seemed to glow. His breath was hideous with the horrible stench of burned flesh. I made the terrible mistake of wounding him, which only made him more ferocious. I was lucky to escape with my life, as I surely would have been his next dinner guest.''"

Trivia

 * The Wendigo is the first Wesen with a name that appears in the English language. However, the English Wendigo is a cognate adopted from the Ojibwe Windigo. In both languages, the word refers to an evil spirit that possesses a person who has previously tasted human flesh, cursing them with an insatiable blood lust. Although in some stories, the Wendigo is not a spirit, but a person who turns into a monster if they commit the crime of cannibalism.