Episode
Proceed with caution, will contain spoilers for the show if you haven't yet seen this episode!
Summary
A demonic shape-shifter adopts the likeness of Sam's college buddy to commit a gruesome murder. When the brothers investigate, the being "borrows" Dean's form to continue its killing spree. (S1 DVD summary)
This episode stars Jared Padalecki as Sam Winchester, Jensen Ackles as Dean Winchester, Amy Grabow as Rebecca Warren, and Aleks Holtz as Zach Warren.