SCP Foundation

Alright. The most noticeable thing when first popping this open is the incorrect image formatting. Consult the How to Write an SCP guide in order to ascertain the correct format. Also, is this image Creative Commons compliant? (Most commonly, this can be dealt with by using a Creative Commons search engine, or with Google's CC image search option.)

• "5x5x4" I assume this is measured in meters, since we use metric units here. Please indicate as such, using either "m" or "meters". Also, when choosing to either abbreviate or spell out measurements, please stay consistent throughout the article.
• The containment procedures are fairly vague. Also, tone is broken quite a few times. Such as:

"Feeding should take place daily consisting of various fruits, vegetables, and insects."

I would restate this to sound a little more clinical. Also, stating that it is fed a standard chimpanzee diet is also okay. (Even works better, in some cases.)

"In the event of containment breach, an alert should be sounded, instructing all personnel to stay in well-lit rooms and have bright lamps switched on in the event of a power failure."

While you're not wrong, this again doesn't sound very clinical. "In the event of a containment breach, personnel are to be instructed to remain in secure and well-lit environments", or something of the sort.

• Also, that image should be at the top of the article, in correct formatting. Not breaking text between the containment procedures and the description. Oh, and, while I'm at it, the rating module also goes at the top. Not the bottom. (Order - Rating Module, Image Template, SCP article)
• The entire first paragraph of the description is not in clinical tone, save for giving measurements of the scip. (For reference, scip is a shorthand/nickname for an SCP article.) The rest can really be summarized to "SCP-XXXX shows behavior similar to a non-anomalous chimpanzee when in a well-lit environment." Maybe you should specify an exact measurement of lux as to what this scip considers "well-lit".
• This next paragraph is just a sort of hacked description of a were-chimp.

At night, or when in dimly-lit/dark rooms, SCP-XXXX becomes extremely violent, becoming significantly faster and stronger.

"When exposed to an environment with a brightness under __ lux, SCP-XXXX begins to react violently, showing a significant increase in physical capability."

she

Okay. Don't refer to a scip, ever, with a pronoun other than "it" or "they".

• The rest of this paragraph is really just a description of what the scip does when it finds a victim. I'm not so sure what to think about it. The whole "turn to stone" thing seems a bit cliche/generic for my liking.

Overall: The article definitely needs work with clinical tone. I am not the best at correcting these errors myself, as I often have issues writing / rewriting ideas that are not mine. Try using less adjectives, and more physical descriptor, and succinct summaries of effects / events.
The idea in itself is not inherently interesting. It's yet another entry of "creature what kills people", even worse when only in the dark. This almost seems like you wrote this purely to try and get it shoehorned into Containment Breach. (Which, unfortunately, is a thing people try and do. Note that we are not affiliated with CB and that it is a separate work/entity.)