SCP 5031
The SCP Foundation. Most of you are probably familiar. Almost all of you have probably at least heard of it. Originally started by some weird fiction aficionados from 4chan (this was back before it was a nazi shit-swamp, when it was simply an ordinary shit-swamp), the Special Containment Procedures Foundation is a (very loose) continuity of short stories that take the form of in-universe case files from a paranormal containment agency. The SCP Foundation scours the world for monsters, cursed items, reality distortions, etc, puts them away in secure facilities, and tries to make people forget they ever existed.
Since the heart of the SCP project is a wiki that anyone can add to, the quality of the entries is...well, about as variable as you'd expect. And also as consistent as you'd expect, but that aspect is a feature rather than a bug. Since its inception, the project has had a strongly anti-canon approach. Multiple overlapping continuities exist within the SCP mythos as writers connect their additions with one another's, recurring characters within the organization start to emerge, etc, but they all contradict each other just as strongly as they tie into one another. It's a textbook example of a pick-and-choose setting, and was always intended as such.
With the amount of popularity, spin-off media, and general pop-cultural penetration the SCPF has enjoyed over the couple of decades since its inception, it's also an aspirational example of ground-up collaborative fiction managing to hold its own even in an increasingly corporate-controlled media landscape.
Anyway. SCP-5031 is an interesting case within the project's own continuity space. It seems to almost be a commentary on the different visions that various writers have had about the world of the SCP Foundation, particularly when it comes to their portrayal of the fictional organization itself. Reading some entries by some contributors, one would get the impression that the SCP Foundation is a heroic organization doing everything it can to protect humanity from supernatural horrors and sometimes having to make hard choices and painful sacrifices to do so. Others (probably the majority) have it as a dystopian, illuminati-like conspiracy horror nightmare with its tendrils corrupting nations from within, and its leaders posing more of a threat to human wellbeing than the monsters and artifacts themselves do. Sometimes it's portrayed as a hypercompetent organization with hundreds of thousands of fanatical agents and unlimited material resources. Other times, an underfunded, in-over-its-head bureaucracy that's about to fall apart under organizational stresses or get suborned by its own "imprisoned" monsters (if it hasn't already been). And everything in between.
So, case 5031 sits on the nexus between these attitudes toward the setting, tugging a little on all of them and seeming to intentionally bounce them off of each other. I also feel like it's throwing shade on some overused monster concepts by grabbing some of the most recurring traits from insipid SCP "creature feature" articles and then pulling the rug out from under them.
The contained entity itself is a vaguely Silent Hill-looking monster that seems to phase out of existence entirely while being looked at, but viciously kills and eats anything it can sneak up behind. It doesn't show up on cameras either; the only way they even know what it looks like is from watching its shadow. The initial case file implies that the creature was found terrorizing a suburban community, as insipid creature-feature SCP's often are, and was taken captive by a Foundation field team after a difficult battle. Said file also has instructions in place for keeping the beast safely contained within a featureless steel vault, and recommendations to avoid poking at it any further.
However, this case file also has a header added to it, written in a somewhat frustrated-behind-a-mask-of-professional-neutrality tone, saying that this document is out of date and in need of revision on account of subsequent research on the imprisoned SCP-5031.
What follows is the journal of a newly promoted SCP Foundation research director as he takes over this particular blacksite, familiarizes himself with its contents, and is promptly appalled at this creature having been thrown in a box and forgotten about for ten years.
The initial file didn't even mention that the monster had been screaming nonstop for years since its imprisonment.
The new site director makes changes to SCP-5031's cell, including trying different foods, music and other sounds, etc, and noting the effects on the creature's behavior. Music and better food seem to make it scream less. Introducing toys for it to play with stops the screaming entirely, though it takes it a while to learn how to play with the balls and other objects given to it without damaging them. It also demonstrates the ability to choose favourite toys, meals, and ambience from lists of options, and to understand symbolic representations of these options well enough to indicate its choice.
One memorable line, describing the creature amusing itself with bowling and basketballs given to itself, mentions its manually dexterity improving with practice, and it currently being at the level of "a human toddler."
Another, even more memorable section, is the following:
"SCP-5031's stress levels rose immediately and drastically" is a line that got to me. Especially juxtaposed with its attitude toward living creatures demonstrated previously, when it was starving and frightened either in the wild or during its earlier captivity.
After this point, the director starts cautiously introducing blindfolded caretakers to the cell, and the creature not only doesn't harm them, but also begins to demonstrate preferences for some human handlers over others.
...
The way it's all written feels a lot like the communication experiments that real life scientists have done with apes, or cetaceans. I get the impression the author of this piece has read some primatology research papers.
...
Typical of SCP articles, the origins of this creature are never revealed. The implication is very clear that wherever it came from - other planet, other dimension, who knows - it arrived on Earth as a feral child, and underneath the ferality it has the same self-awareness, emotional range, and possibly the same intelligence as a human child.
Eventually, it learns to arrange letter-blocks to proactively communicate with its handlers. And also, after being given opportunities to mix and match its foodstuff and to play with increasingly complicated mechanical toys, to prepare its own meals and compose its own piano music. A watershed moment comes when the director and its favorite in-person handler give it an excess of ingredients and lets it cook in sufficient quantities to serve in the facility's cafeteria for lunch that day. The final journal entry reads as follows:
I spent the entire read waiting for the other shoe to drop. Either for the monster to have been tricking them into letting their guard down, or for some random mishap to cause it to flip out and rampage, or for the director to be replaced by a new one who sends the monster back to eternal solitary confinement while cackling and twirling his moustache, or for the CURRENT director to take off the mask and go "we've learned all we can, time for the dissection." But nope, it never happens.
Apparently, some later contributors even have SCP-5031 taking part in the Foundation's field operations, fighting worse monsters alongside its favourite humans.
Friendly and/or cooperative creatures in SCPF captivity are nothing new to the project, and neither is the concept of the organization using some of its wards as assets in various capacities. There have also always been the occasional wholesome/feelgood articles sprinkled around for variety, in moderation. You don't normally see them co-occuring with the "don't even blink" type monsters, though. Or with the "SCP Foundation is running torture pits" portrayals of the organization, or even the "there are differences of attitude and methodology within the organization itself" ones.
Like I said, Case 5031 almost seems to be more about the different attitudes of the WRITERS than it is about different sides of the fictional agency and setting.