Thought I'd would write this again seen as my account was deactivated or something like that for whatever reason. Also made some improvements too.
But anyway, I have found an image on the Visual Records page that caught my eye.
Here's the link: http://visual-records.wdfiles.com/local--files/humanoid/tumblr_mzemt4KPji1t5doy7o1_500.jpg Pretty creepy…
And here's what I came up with when observing:
Description, it appears to be a "mass of fabric string-like material maintaining humanoid embodiment", I might use that line actually ;D. So I thought the loose strings, or "tentacles" or "appendages", maybe could extend and possibly infest its cell and cause "damage", and possibly envelop staff in its strings, and leave no traces possibly. photo itself looks as if it has undergone some sort of corrosion or deterioration, so maybe any photograph or artistic depiction of the SCP will slowly deteriorate. And also, the "damage" caused when infesting could be deterioration too, I guess deterioration could be its thing. The entity looks in a kind of "dormant" state, so I thought the SCP could be very immobile in humanoid form, like in the picture, and could be very mobile when infesting with its strings. Finally, there appears to be a chair that the entity sits on, now I doubt the foundation provides furniture for its subjects, so the chair could possibly an SCP-XXXX-1? Maybe there can be a bit of a backstory behind it? And have its own anomalous effects? I don't know…
Special Containment Procedures, now I don't want the SCP to deteriorate its way through everything, so there must be a certain material that the SCP cannot deteriorate, and what the cell must be constructed of, maybe concrete or glass that I just wierdly thought of. If the SCP is seen to be infesting a certain could be released to make return to humanoid form. No personnel are to enter the cell in fear of being abducted and enveloped in the SCP strings.
Addenda, I was mainly going to put notes on behaviour in addenda and SCP-XXXX-1's anomalous effects, but I wanted to include more of a backstory between the SCP and SCP-XXXX-1 to make the SCP sound more interesting and mysterious.