One of the earliest and most iconic creepypasta characters.
The original image of Jeff associated with the story is a photoshopped image of a video still of a middle-aged Asian woman approaching the camera, at which point her face appeared quite white - the photoshop embellished the whiteness of her face further, among other things, becoming the iconic image. It was spread around the Japanese Internet, 2ch in particular, as a surprise/shock image before making its way to the English-speaking Internet. May have some connection to Kuchisake-onna.
In late 2022 and early 2023, as part of the trend of AI-generated art using img2img to create pareidolia-inducing images, several creepypasta images, such as Jeff's, would be inserted to create cute anime girls, to be shared around and cause mental damage to those who look upon them. These AI anime girls in turn have inspired fanart of their own, including those based on Jeff.