Project Nemesis is a fan driven website for games that use the One-Roll Engine (like Nemesis, Wild Talents, Reign and Monsters) or Chaosium's Basic Roleplay System (BRP) (like Call of Cthulhu) and the Delta Green setting.
A collection of folders in a zip file, normally given some innocuous or random name (stuff.zip or HSKDfjeik.zip). Most of the images are pornographic, but they have a tendency toward the more extreme, internet-based fetish pornography. These are often focused around extreme physical changes to the human body, hermaphroditic qualities or animal-human hybrids, and often in violent situations.
Some involve characters from childrens cartoons. The level of the artwork and the style varies dramatically, as do the subjects. There is little writing, except for some of the files that are have Japanese writing. Scattered throughout these files are poorly executed designs of various Mythos critters, particularly Y'golonac, Tsathoggua and Eihort.
Most of these images were clearly designed using Microsoft paint, and yet despite their low quality they are stylistically arresting and disturbing (0/1 SAN loss). These files have been occasionally found on file-sharing networks but strangely enough, most of the time the zip file is found on a hard copy disk of some kind.