SCP Foundation

standard humanoid containment chamber.

I've generally seen this be capitalised in final products - 'Standard Humanoid Containment Chamber'.

Any unusual behavior observed must be reported to Dr. Cornell immediately. Interviews of SCP-XXXX are only to be conducted by Dr. Cornell, with O5 approval.

It's not a good idea to have a named doctor for people to report to, because, in-universe, they could get sick, die, or simply move location. Instead, use a generic term instead like 'Project Head', which can have a changing person but it always an existing role. Additionally, why does the doctor need O5 permission to interview an Euclid humanoid?

SCP-XXXX is a humanoid entity, approximately 1.85 meters in height. SCP-XXXX's appearance is that of a crudely-drawn stick figure, reddish-brown in color aside from its eyes, which appear as oval-shaped holes in its head.

I would change this over a little to something like 'SCP-XXXX is a humanoid entity with an appearance similar to that of a crudely-drawn stick figure, with a reddish-brown [maybe change to 'copper' or 'auburn'] colour, standing at 1.85 meters in height.' [I don't see why you need to mention the eyes as oval holes in the head when talking about colour].

Okay, so on to some questions about this choice in object.

• Is it 2D? If so, how does it support itself?
• Does it have hands and feet, as I've seen stick figures drawn both with and without them.
• Why is it that thing? Why did you chose this, why is this the object that causes this effect?
• In-universe, why does it exist, who made it, why did they make it do this?

through the gaps in its body

You mentioned the gaps for the eyes, but what are the other 'gaps in its body'?

Analysis of samples taken from SCP-XXXX shows that it is composed of a mixture of spray paint, acrylic paint, and [REDACTED].

I don't know why this last bit would be redacted. Is it something anomalous that makes it somehow mobile and/or sentient? If so, it's not indicated enough to make the reader think that and therefore consider it mysterious - instead, it feels like the author wasn't sure what to put here, and therefore used this to get out of a sticky situation. I advise you to read this guide to find out more about the 'art' of blocking out information.

SCP-XXXX's form appears to be unstable, flickering back and forth approximately 120 times per second.

This isn't quite clear what you mean. Do you mean like a frame rate, or does it disappear for a nano second, or what?

SCP-XXXX is incapable of auditory communication.

It would probably just be more simple and clearer to say 'SCP-XXXX cannot vocalise'. Things don't always have to be said in a more complicated way just because it's a pseudo-scientific article.

However, it can communicate via words that visually manifest near its head for a period ranging from seven to ten seconds before dematerializing.

Much like the flickering, more information would be good to explain how this looks. Does it appear in a speech bubble, or just the word/s?

SCP-XXXX has demonstrated a wide vocabulary, yet it prefers manifesting only a few words at a time.

How is it know it has a wide vocabulary? You may not have to explain this in your article, but you as the author should know, and then your resulting product should reflect that.

SCP-XXXX appears to suffer from various mental illnesses, including depression, anxiety, and minor schizophrenia

'Minor schizophrenia' generally isn't used as a term - you could use 'mild schizophrenia', or 'schizoaffective disorder', which includes depression.

Autopsy reports show that subject died of an overdose of the drug ██████████████.

Why is this hidden?

Blood samples from ██████ did not match up with the [REDACTED] found in SCP-XXXX's composition.

So you hint that it's something organic/biological, but it's still not really enough to explain why you've blackboxed it, in my opinion.

All in all, this thing doesn't actually do anything. It seems like maybe it had either killed or convinced its creator to commit suicide, but beyond that, it doesn't seem to have many anomalous effects. Of course, its very existence is anomalous, but why it has to be interviewed by only one doctor and why these interviews have to be okayed by O5 is still unclear. Hell, why it is Euclid, not Safe, is also unclear. It seems pretty 'Safe' to me.