The Trickster

The Trickster plays a unique role in the show, in that he's not entirely against or with the Winchester brothers. Although he plays an antagonistic role in both of his appearances, he does not kill either of the hunters when given the chance, and even attempts to teach Sam a valuable lesson. He even goes as far as turning back time so that Dean's death can be reversed, but only after warning Sam that he would have to learn how to let his brother go. Nonetheless, his morbid sense of humor isn't shared by the brothers, and his playful pranks usually end up being brutally violent or completely fatal. Hence why he is their target to be slain in both the episodes he appears in.

Powers and abilities
He can effortlessly create anything from thin air, whether it be chainsaw wielding psychopaths, scantily clad women, food, and even an exact duplicate of himself. Each creation of his functions as it would as if it were real, even being entirely capable of harming others and having the capacity to live and die. He has also displayed a potent degree of time manipulation, being able to trap an entire town in a time loop, and yet singling out only Sam as being completely aware of it. He can also turn back time to seemingly any point he wishes, going so far as to send Sam back several months and preventing Dean's death (for the time being). He has also displayed the ability to disguise himself (although he generally maintains a central human image), as well as possessing telekinetic abilites (as seen when he telekinetically retrieves the stake from Sam), and he is effectively immortal. The only thing capable of killing him is a special kind of stake dipped in the blood of his victim, and even then he has managed to escape being killed several times.

Appearances
Tall Tales 

Mystery Spot