Ehrenreich’s first acting gig was in the second ever episode for "Supernatural," titled “Wendigo.” Ehrenreich plays the brother of a guy taken by the Wendigo, and Winchester brothers Sam and Dean (Jensen Ackles and Jared Padalecki) lead him and his sister (Gina Holden) into the woods to find him.
Fans consider the "Wendigo" episode one of the series' worst outings, but it didn't seem to hurt him. Or maybe it did - after "Supernatural," Ehrenreich had only bit parts for several years, but he finally started getting steady work in the last few years, finally turning heads in the films Rules Don't Apply and Hail, Caesar!
Here's a clip of Ehrenreich's appearance on "Supernatural."
His appearance on the show proves the adage: it's not how you start, it's how you finish.