SCP-055
SCP-055 is a "self-keeping secret" or "anti-meme". Information about SCP-055's physical appearance as well as its nature, behavior, and origins is self-classifying. To clarify: How Site 19 originally acquired SCP-055 is unknown.
About This SCP
SCP-055 by qntm and CptBellman, from the SCP Wiki.SCP Foundation logoCC BY-SA 3.0