Serial Killer Shapeshifter

The Serial Killer Shapeshifter was a shapeshifter who acted as a serial killer.

Weaknesses

 * Silver - Dean killed the shapeshifter with silver bullets.
 * Retinal Flare - The shapeshifter could be identified by its retinal flare on cameras.

Trivia

 * This is the first shapeshifter that Sam and Dean have ever encountered in their lives given their comments while fighting it.