Ludensky

Professor Ludensky, was a teacher at the collage, Michael, Brian and Kate went to, and was also secretly a pureblood Werewolf.

History
Cursed to be a werewolf, as a pureblood, he was able to control his monsterous nature, and lived off animal hearts, however he had a failing in 1999, where he killed a person and ate there heart. He managed to control his beastly nature, and keep himself hidden, well aware that hunters would come looking. He managed to keep himself under control, untill 2013, where he again lost control and killed another person. Attracting Sam and Dean to him.

Several nights later, while out in the woods hunting, he ran into Michael and attacked him, but managed to regain control at the last minute and left him, unaware he had already passed the curse onto him. In another attack, where he killed another person for there heart, he accidentall dropped his ring. Which allowed Brian's roomate Brian to track him down.

Confronting him Brain told him he new what he was, and threatening him with a silver knife, made Ludensky bite him, thus making him also a werewolf. Brain then tipped off Sam and Dean to him, who confronted him, a fight broke out and although Ludnsky managed to get the upper hand, Dean shot him with a silver bullet, his last words thanking the hunters for freeing him of the curse