Jake is a minion of Crowley.
While Dean is drowning his sorrows at the Milton, he notices Jake wearing a rosary around his wrists and as he leaves his bar stool, pull out a knife and pursue Crowley to the bathroom. Dean knowing a hunter when he sees one, quickly stops Jake from entering the bathroom, knowing he wouldn't stand a chance against a demon with a knife. Dean appeals to him that if he goes through with it, not only will Crowley kill him, but everyone he knows and loves. Jake reveals he has a kid sister to Dean, and that he will not go after Crowley for her sake.
As Dean leaves the Milton, Jake approaches Crowley telling him he was worried that Dean figured out he was a demon, but that Crowley was right and Dean saved him.
Powers and AbilitiesEdit
Although no much known about his power and abilities, he had black colored eye. Indicating he was lesser ranked, common demon, and presumably had standard abilities of lower-tier demons.