Eye Sigil ARG/Kingdom of Loathing
Release Date: 10/2/2003
Status: Sigil found, Piece not found
Kingdom of Loathing is a browser-based, multiplayer role-playing game designed and operated by Asymmetric Publications.
The sigil can be seen on Conspiracy Island, by going into the Government Lab. There, the player encounters a weird door. Despite extensive searching, a puzzle piece has not yet been discovered.
Ungawa wrote a short guide about how to get from level 1 to 11 instantaneously with 1 fight, which is necessary to be able to survive on Conspiracy Island to solve the game for the sigil ARG.
After hitting 11, you still need a bunch of buffs to be able to survive well. Get them here.