Oskar was the son of a peasant Polish family, who gave aid and shelter to Rowena 300 years ago.
When Rowena was forced to leave her home 300 years ago, she found aid with a peasant Polish family. Over time, Rowena grew to care for their eight-year-old son Oskar who also grew fond of her and even called her "Auntie Rowena". Upon learning that he was terminally ill, she decided to give the family a gift for their kindness, and cured Oskar with a spell. She also cast a second spell that would take root when Oskar became fully grown, making him immortal.
At some point, Oskar traveled to Ecuador and learned how to roast coffee beans. He eventually became a counter server, taking the name "Seth".
After learning of him from Olivette, Crowley found Oskar working, and ordered a meal from him. He said he enjoyed the coffee, and learned that he wanted to go to Asia. Crowley told Oskar that he was in the business of making dreams come true, but left when Sam Winchester, in the guise of Dean, called him for help.
After learning that Rowena would have to kill something she loved to remove the Mark of Cain from Dean Winchester's arm, Crowley went back to Oskar and took out all of his customers. He approached Oskar, and revealed that he knew what the witch Rowena had done for him, and brought him to Rowena and Castiel.
Rowena was surprised to see Oskar again, and after embracing him in a hug, she stabbed him in the neck with a pen, killing him. She collected his blood in the bowl with the quince and remains of the golden calf, as it was the third ingredient needed to remove the Mark from Dean's arm.
Powers and AbilitiesEdit
- Mortality - Although he was immortal, his immortality has certain limits. He could still die due to natural or unnatural causes. It was proven when he was killed by Rowena with a fatal stab of a little iron stake in the neck.