|Actor|| Aleks Holtz|
|Dates||???? – 2005 (killed by Dean Winchester)|
|Location||St. Louis, Missouri|
Little is known of the shapeshifter's past other than as a child it was "hideous and hated", choosing to take out its rage by assuming the identities of strangers and brutally murdering their loved ones. The shifter appeared to derive great pleasure from killing, and seemed to prefer to target women.
The shifter assumed the identity of Zach Warren and proceeded to violently murder his girlfriend, Emily. The murder came to the attention of Sam and Dean Winchester who quickly deduced that they were dealing with something supernatural after seeing a retinal flare on some security footage. Some time after framing Zach for Emily's murder, the shifter took on the form of a businessman named Alex and attacked his wife Lindsay while he was away on a business trip. When Alex came home early, he caught the shifter torturing Lindsay, forcing the shifter to knock him out and flee.
Realizing they are dealing with a shapeshifter after hearing Alex's story, Sam and Dean investigate the sewers, where they find the shapeshifter's lair and are attacked by it. The shifter flees when Sam and Dean begin shooting at it and when the Winchesters go after it, the shapeshifter ambushes Dean, locks him in its lair, and sheds its skin to take on Dean's appearance. The shifter attempts to trick Sam, but Sam is able to see through its tricks. When he hesitates to kill it, however, the shifter knocks Sam unconscious.
The shifter turns its attention to Zach's sister Rebecca Warren, and attacks and ties her up after she lets him into her house under the assumption it was Dean. Before the shifter could kill Rebecca, the police arrive due to Sam and Dean escaping and it is forced to run, implicating Dean in its crimes. After escaping, the shapeshifter returns and takes Rebecca captive, leaving her in its sewer lair to be found and rescued by Dean.
The shapeshifter pretends to be Rebecca and attacks Sam, knocking him out and tying him up before assuming Dean's form once more. The shapeshifter reveals that it plans to frame Dean for the murder of Sam so he will be hunted for the rest of his life. Sam is able to free himself but is overpowered by the shapeshifter which starts to strangle him to death. Dean arrives and shoots the shapeshifter twice in the heart with silver bullets, killing it. As the shapeshifter was caught in the act of trying to kill Rebecca in Dean's form, Dean is blamed and Zach and Alex are released. The shapeshifter is buried as Dean Winchester, allowing Dean to fake his death.