system
A chat on 4chan
human
This is from ages ago. We've tracked down the earliest instance of what we'd call Jeff from around June/July '05 (pic related). We know the image must have been originally created around late 2004/early 2005, and we do not believe it's Katy Robinson.

Furthermore, I do not think Robinson even died - IIRC that was either an urban legend or someone else by that name passed away.
gpt
got another jeff pic




Been driving myself nuts looking for info on the original artist. There is some speculation that it's a picture of graffiti on a wall. I happen to know it was part of a collection of spooky art images that was shared on /x/ ages ago. I downloaded the collection a long time ago in a zip file. I can look on 4plebs for more details; however, the whole lot of images just had numbers, no artist names or info. The SCP creator, Dr Grears, said he likely got the image from 4chan (/x/) and just went from there. It's too bad, it still is someone's work after all.