Jeff the Killer

Jeff the Killer is a classic Creepypasta character created by a YouTuber named "Sesseur" around October 2008 that was based around a Photoshopped image of a pale man with no nose and black eyes with white and black pupils, a long canine-like smile, with a white coat on in a dark room with laundry hanging with the light of the moon illuminating it from a window in the background.

Despite the picture becoming a part of a Creepypasta story and originating potentially from a Japanese website, it is now known as a widely popular internet jumpscare image, and has even inspired costumes, entire movies, and even political moments as well, and has moved on into the status of more of an urban legend in the same way as the Slenderman, also a very similar case as well. (Although no real crimes were committed based on this.)

Image Origin(s)
There are many theories to where the original image came from. All of these are all still yet to be proven.

Before the Creepypasta appeared, the image is known to first appeared on a Japanese site around the year of 2005, along with another one which is believed to be the "less-photoshopped" one. There are two page links of the images, including a timeline to where they supposedly came from.

It is also rumored to be of an overweight Japanese girl in a room with hanging laundry who spammed her image across the Japanese image board, 2chan in 2004, before making it’s way to 4chan throughout the later years, and there was a Photoshop contest where people took turns Photoshopping her photo to see how “good” they can make her look. Although this theory is still yet to be proven.

There is currently a subreddit which is trying to find the original image.

AUTHOR'S NOTE : I've gotten some responses so far to where the original Jeff the Killer pictures supposedly came from. First off, the unedited photo was apparently of a girl pulling a stupid face in a dark room; and because of the camera flash blocked her face, it looked kind of creepy and that's probably the reason why it got photoshopped by users in her 4chan posts. The second user determined that she supposedly spammed this picture on a 420chan /b/ thread and her responses were the same results in prior to her original post on 4chan. The third one stated that the girl's name was Victoria, and the other pictures she had posted on 4chan were unrelated and irrelevant to the one she took.

Beforehand, I began to go into further analysis to see who the girl behind the Katy Robinson photo was. By doing a reverse image search attempt, what I've stumbled upon was that her old photo originally appeared on the TrueChristian.org site and it occurred in the owner's hate e-mail pages. The girl's name wasn't Katy Robinson, it is Heather White. I've contacted her on Facebook and she said that she wasn't the girl who appeared on 4chan at the time and hoped that the people who took her identity gets their pages and accounts shut down.

History
History of the image and its appearance on screamers.

The oldest documented appearance on the entire internet about Go to Sleep is on the Japanese site pya.cc where two versions of the image were posted. The first publication, made on September 10, 2005 by Maruhorando, was named 白粉そ の ２)(White powder referring to Cocaine.)while the second was published on November 16 of the same year by Omega Boruto. Both two years before appearing on YouTube and three years before the Jeff the Killer creepypasta emerged.

On August 2, 2007, a Japanese video named NNN臨時放送(NNN Extra Broadcast) was uploaded to YouTube. This one tried to simulate an intrusion of a television signal putting disturbing images, among them, the one published by Omega Boruto. By this time, it is believed that the image was better known in Japan than in the rest of the world.

A year later, in August 2008, Newgrounds user killerjeff posts the image on the site claiming to be a photograph of him. It is believed that this is where the Jeff the Killer creepypasta arises, since in October of that year a story based on that image was uploaded to YouTube. Around this time, the page nne.jpg was also created, a screamer that was spread on 4chan and other forums with the phrase "Go to Sleep" that was intended to scare users who surfed at night.

Since 2008, Jeff the Killer's creepypasta has become too popular, becoming an icon of this sub-genre of stories.