"Feeny's not the killer, I am."
- — Shawn
In Shawn's nightmare, Killer Shawn is the murderer who kills Kenny, Feeny, Feffy, the Creepy Janitor, Eric, Jack, and Angela. His identity as Shawn isn't revealed until the end up the episode, when the real Shawn unmasks him to reveal him.
The intent of Killer Shawn is to reunite Cory and Topanga, who had recently broken up. Killer Shawn is in Shawn's dreams because Shawn feels responsible for the breakup of Cory and Topanga. After Shawn wakes up and shares his dream, though, Feeny, Cory, and Topanga tell Shawn that it isn't his fault.
At the tag of the episode, Killer Shawn jumps out from behind a shelf in the real world, adding some terror to the end of the episode.