First, What is a Wendigo?
Nathan Calson, a Canadian historian described the Wendigo as a large monster, 15 ft. tall always naked, with owl-like eyes that glow red and long pointed claws. It's hair is long and matted. This creature was a human before being transformed by a spirit into an apparition that eats flesh, human flesh, the more it eats, the more it wants.
The Case of "Swift Runner"
The priests listening to his story became suspicious. How could that be? Emergency food was within 25 miles of Swift Runner's camp at a Hudson's Bay Outpost and it didn't look like he was starving to death, he was overweight, 200 lbs. +
He later confessed to killing and eating his six children, but only to survive.
They still didn't believe him, since he was within hiking distance to the emergency food and willingly decided to eat every last bit of flesh, except the teeth and bones. Apparently, there were knife marks on the bones which matched Swift Runner's hunting knife.
The priests determined it wasn't just a case of cannibalism for survival, but Swift Runner suffered from Wendigo Psychosis, a medical term for a factual historical phenomenon. He was tried, found guilty and executed for his crimes.
The Wendingo legend still survives, told by Indian Chiefs and Shamans, among the Prairie Indians.