Killer arrive to outertale with a mission from his boss Nightmare: kill citizens and get souls. Killer was smart and agile, so he quickly managed to kill several monsters and humans without being noticed, having fun while doing it. However, one target in particular caught his attention: Outer Sans:

"Hmm, interesting...."

Killer started following Outer in stalker mode, trying not to let him notice him. He followed him through the crowd trying not to be noticed or appear suspicious, slowly getting closer and closer. Once he had had enough fun, he grabbed him, holding his hands and putting the knife to his neck:

"Heh, it's a shame that a being as cute as you has to die."