Jeff the Killer is a fictional character from an internet horror story known as a creepypasta. He is depicted as a disfigured young man with pale skin, dark hair, and a haunting smile. The story describes his transformation into a killer after a series of traumatic events, including bullying and a fire that left him scarred. The character gained popularity through various online forums and social media, inspiring fan art, videos, and adaptations. Creepypasta stories like Jeff's often explore themes of fear and the supernatural, contributing to the broader genre of internet horror fiction.