in case i don't write very clearly: it's a very vaguely human-shaped thing that is always trying to move in one direction. it can walk through everything that doesn't have a strong electrical charge, and occasionally it has extrusions that it uses to mess with solid things and/or stimulate your expunged data with extreme prejudice.
yoric wrote a story about it: http://scp-wiki.wikidot.com/encounter
i'm told all it really needs now is a picture. i'm working on that bit by making a life-size SCP-XXX, but until it's finished, critique of the actual writing would be marvelous.