Cyrus McMahon

In 1982 terror gripped the city of San Gabriel. A serial killer had murdered at least 9 people and left the bodies with the tongues removed. Detectives struggled to track down the man who the reporters called the Tongue Twister leading to weeks of fear for all the mortal residents of the city.
What they did not know was that the Tongue Twister was actually Cyrus McMahon, a hedge wizard who'd gotten himself possessed by a spirit of hunger, warping his mind and driving him to cannibalism. The true nightmare of this possession though was that despite the primal spirit reducing him to a being driving solely by the animal instinct to feed Cyrus retained his command over magic making him an incredibly dangerous killer.
He was eventually killed by a group hired by the council to handle the situation before Cyrus revealed things which couldn't be easily covered up to the mortal community. When his body was found by human detectives the official story was that Cyrus was infected with a rare prion disease which drove him to his cannibalistic insanity.