Man's best friend, now Chernobyl's most radioactive stray.
A photo of SCP-9427 captured right before containment.
Special Containment Procedures: SCP-9427 is to be kept in an 18.6-square-meter room lined with a 30.5-centimeter-thick lead interior, followed by a 1.5-meter-thick concrete outer wall to allow researchers to observe SCP-9427. Observation is to be conducted exclusively through a leaded, radiation-shielded viewing port built into the containment wall; this system allows visual monitoring of SCP-9427 without direct radiation exposure risk. A single black, ballistic nylon dog bed shall be positioned in the right corner of the cell. Nothing else is allowed in the cell due to containment concerns, save for approved research equipment. Toys are not permitted under any circumstances, regardless of whether they remain in containment. Researchers are instructed to lead SCP-9427 as far away from its bed as possible prior to interaction to avoid repeated degradation and replacement. SCP-9427 is not permitted to leave its containment under any circumstances; exposure outside of its containment will lead to rapid, lethal contamination of the facility and pose safety risks to Foundation personnel.
A wash-down station is positioned in a 4.6-square-meter room to the left of the hallway leading into SCP-9427's containment cell. All personnel are required to have their radiation exposure measured before and after interaction with SCP-9427, both direct and indirect.
When interacting with SCP-9427, personnel must wear white Level A suits and self-contained breathing apparatuses to prevent all direct dermal or respiratory exposure. Personnel are required to carry Geiger counters and KI tablets, consuming at least one tablet before entry. Thermoluminescent dosimeters are strongly recommended but not mandatory. If SCP-9427's radiation output spikes, personnel are to immediately exit and remain in the adjoining hallway until cleared by monitoring staff. SCP-9427 has been observed to wait near the containment door during scheduled interaction periods; personnel intending to interact with the subject must wait for it to move away from the door before entering.
SCP-9427's radiation levels are to be continuously monitored for fluctuation. All dosimetry equipment used on-site is calibrated to a maximum threshold of 30,000 roentgen per hour (R/h); readings above this value are considered instrument saturation and are extrapolated. Biological and physical samples may be collected, provided SCP-9427 remains calm, and must be stored in lead-lined containment boxes. Approved samples include fur clippings and saliva swabs.
Description: SCP-9427 was first observed outside the ruins of the Chernobyl nuclear disaster the day after the reactor meltdown, found on April 27, 1986. It was initially identified as among the most radioactive objects recorded at the site, though Soviet first responders were primarily focused on reactor containment operations at the time. SCP-9427 appears to be a medium-sized domestic canine (canis lupus familiaris) standing 58.4 centimeters tall, with a 61-centimeter chest girth and a 45.7-centimeter back length, and weighing 23.1 kilograms. Its sex remains indeterminate even after genetic testing, as no stable or recoverable baseline DNA profile has been identified, nor are any identifying physical features observed. Its breed is similarly unidentifiable, though it appears to be a mixed-breed canine exhibiting atypical blue pigmentation. Whether this pigmentation predates the incident is unknown. It wears a navy blue collar with a round, golden piece of metal engraved with "четыре." This has led researchers to believe SCP-9427's name is "Four," though no corresponding owner records have been identified from the cities of Prypiat or Chornobyl. The numerical designation has raised the possibility that SCP-9427 was not the only subject of its kind present in the affected area, but officials found no other animals present. For ease of communication, scientists have referred to the subject either by its number or as "The Chernobyl Canine."
The subject was initially targeted for termination by Soviet personnel in accordance with standard decontamination procedures; however, projectiles were observed to deform and partially liquefy before impact, consistent with exposure to extreme localized field effects surrounding the subject. The entity remained unaffected and continued normal locomotion. Personnel involved in the engagement subsequently developed acute radiation sickness consistent with extreme environmental exposure, despite not venturing onto the roof of Reactor 4. The subject was later retrieved by a state research team for study; all individuals involved in the initial handling effort expired within 72 hours. Irregularities in survivability and environmental radiation behavior prompted investigation by the Foundation, which subsequently secured the subject for containment.
Initial radiation readings at the time of recovery measured approximately 5 roentgen per second (R/s), or ~18,000 R/h. Due to repeated instrument saturation, later readings are considered estimates derived from environmental degradation modeling. SCP-9427’s radiation output has remained broadly stable since recovery, with fluctuations correlated to behavioral and emotional state.
When awake, alert, and in a neutral emotional state, SCP-9427’s emissions remain consistent with baseline measurements. When agitated, excited, surprised, or distressed, output may increase to an estimated 8 R/s (~29,000 R/h), persisting until the subject returns to baseline. During dormant states, emissions decrease to approximately 4 R/s (~14,500 R/h), though direct analysis during this period is limited due to increased sensory responsiveness; entry into containment is typically sufficient to rouse the subject. Testing has shown that the subject's olfactory, auditory, and visual sensitivity compared to standard canines are significantly heightened, with SCP-9427 able to smell a rib-eye steak nearly 1.6 kilometers away.
Why SCP-9427's radiation levels have not decayed is unknown. The most abundant isotopes found on its fur and in its blood are iodine, strontium, cesium, and various types of plutonium, most of which have half-lives of less than 30 years. In addition, SCP-9427 exhibits a localized emission field approximately 30 centimeters from its body surface. During periods of heightened emotional arousal, specifically anger, this field has been observed to produce transient anomalous interactions with nearby matter, including pre-impact structural failure in metallic objects. This phenomenon is currently theorized to be a byproduct of extreme localized ionizing field effects rather than thermal emission, though no complete model has been confirmed. It has not been observed to affect organic life as of yet.
The lifespan of SCP-9427 is unclear. Researchers had expected it to expire soon after arrival due to the sheer radiation present in its body, but as of early 2026, analysis of the subject's DNA shows there has been little to no aging in its cells, consistent with that of a dog around four years of age. The subject's brain has not been affected, either; a scientist's study shows that there has been no decay or effect on the subject's daily functioning.
SCP-9427's behavior is consistent with that of a dog. When personnel enter its containment—specifically, those who SCP-9427 is familiar with—SCP-9427 will jump, wag its tail, and bark. If personnel enter its cell, it will attempt to lick them, dance in circles, and try to play. It appears to understand basic commands in both Russian and Ukrainian, but does not respond consistently to other languages. Personnel are allowed to pet SCP-9427 only on its head for less than 10 seconds.
Personnel interacting with SCP-9427 are subject to strictly timed exposure windows not exceeding 10 minutes per session. Following a standard interaction cycle, absorbed radiation doses are expected to reach approximately 200 roentgen. While protective equipment reduces contamination and ingestion pathways, it does not fully mitigate ionizing radiation exposure.
As a result, all personnel are expected to develop acute radiation sickness following direct interaction, with severity dependent on cumulative exposure frequency. Reported symptoms include nausea, vomiting, fatigue, leukocyte suppression, and █████. Long-term participation in SCP-9427-related procedures is restricted due to elevated incidence of hematological damage and cancer.
Addendum 9427-01: Recovered Interviews
Interviewed: Dr. Konovalyuk
Interviewer: Agent Griffith
Objective: See if Dr. Konovalyuk is at risk of attachment to SCP-9427 or if she can continue to work with the subject.
Note: The following log is pulled from Agent Griffith's body cam and the camera in the interrogation room.
<Begin Log>
Agent Griffith: So, why did they pick you to test 9427? So many others have tried. You must have a secret to your success. Did they know about that beforehand?Dr. Konovalyuk: I'd never been much of a dog person—I have a cat named Muffin who I love with all my heart—so naturally, I was the first pick for testing 9427. Several other scientists hadn't been able to do so. Either they grew too attached to 9427, or—and they'll never admit this—they were too scared. Radiation is a silent killer, after all.
Agent Griffith: And you weren't scared? The few times we've worked together, you seemed to have no fear.
Dr. Konovalyuk offers a grim, tight smile that doesn't reach her eyes. Her hands, clasped together, tighten slightly.
Dr. Konovalyuk: I knew what I was getting myself into when I signed my contract. I've seen colleagues die. Maybe the cause of death wasn't attributed to what we see here, but…
Agent Griffith clears his throat, not quite meeting Dr. Konovalyuk's eyes.
Agent Griffith: Right. So how?
Dr. Konovalyuk leans back in her chair. The overhead light flickers.Dr. Konovalyuk: I don't have any secret to success. But when the job requires something of me, I'm going to deliver. I figured you'd have known that, watching me go into its chamber for testing.
Agent Griffith's lips thin into a grimace.Agent Griffith: Let me get this straight. You are attached to the subject?
Dr. Konovalyuk shrugs. A half-smile dangles from her lips.
Dr. Konovalyuk: I wouldn't consider myself attached. As I said, I'm a cat person. And by all accounts, 9427 functions like a normal dog. Its behavior is cute, yes, but it's a living reactor. Even if I wanted to become attached, it's a bit hard, especially seeing as researchers aren't allowed in the cell unless granted access.
Agent Griffith: Weren't you seen in the containment cell with the subject? Alone, outside of testing hours?
Dr. Konovalyuk's smile freezes. Agent Griffith's face doesn't shift, but one of his fingers taps against the table.
Dr. Konovalyuk: I was approved to take samples. You can ask ██████.
Agent Griffith: I already have. She affirmed. But you could have easily sent in a Class-D to collect that fur. And you were in there for longer than initially approved.
Dr. Konovalyuk takes a moment to respond.
Dr. Konovalyuk: Even if I'm not attached to 9427, it's attached to me. It's seen me enough that I would have the easiest time collecting samples. Its radiation levels only spike when I enter containment and its eyes find me. For others, the levels can stay high the entire time if 9427 feels a certain way about them. Maybe it's because I can speak a few Slavic languages. Maybe I remind it of its home. I'm not really sure.
Agent Griffith: What happens if the levels remain high? Coming from an expert. The notes don't do it justice.
Dr. Konovalyuk lets out a quick, dry laugh devoid of humor.
Dr. Konovalyuk: Well, assuming 9427's radiation doesn't kill them in the time it takes them to leave its cell, they'd better hope all their symptoms are is vomiting.
Agent Griffith: I've read the subject's notes. I thought the gear protected them enough that it's mild radiation poisoning at most.
Dr. Konovalyuk: No. At best, that's what you're going to get. The longer you sit with 9427, the more radiation penetrates your suit, and the more your body is being destroyed. I don't think we've reached the highest levels 9427 can go, but with how many roentgen it gives off, if it's emotionally stimulated for too long, you have twenty minutes until you're dead. I was being hyperbolic before, but while 9427 loves new people, I think it loves them too much. It's not familiar with them, and that excitement spikes its levels. It's a double-edged sword—you can't safely go into its chamber if it's too excited, but you can't let it get to know you to stop that reaction without going inside. Seeing us through a thick pane isn't good enough for an animal.
Agent Griffith looks visibly uncomfortable. He pulls at the collar of his suit. He doesn't reply for a moment, seemingly searching for words.
Agent Griffith: Noted. Your relationship with the subject doesn't seem to be compromising your tests. I hope you can continue to work with it.
Dr. Konovalyuk's smile is sad now. Her face, otherwise, remains stoic. Her voice is strained, though the emotion behind it is unclear.
Dr. Konovalyuk: It's a necessary evil.
<End Log>
Note: Continue to keep watch over Dr. Konovalyuk. Agent Griffith suspects compromisation.
Addendum 9427-02: Recovered Interviews
Interviewed: Valery Pyanykh
Interviewer: Agent Griffith
Objective: Valery Pyanykh was one of the first firefighters to arrive at the scene of Chernobyl, helping to fight the disaster for over a day on and off, and was the first to point out 9427 from a distance. Find out any observations he had.
Note: The following log is pulled from Agent Griffith's body cam and the camera in the interrogation room.
<Begin Log>
Agent Griffith: Thank you for your service all those years ago. I hope your memory isn't too hazy.
Pyanykh: Quite the opposite, actually. I remember every moment of those nights like it's burned into my memory, even when I don't want to.
Agent Griffith: So you remember the subject well, I presume?
Pyanykh: If anything, it's what I remember best.
Agent Griffith: What did you first observe?
Pyanykh: I saw it from a distance. At first, I thought it was a piece of fabric that had somehow flown out of the plant… or something along those lines. I mean, this close to the reactor, you're not expecting to see a dog, especially after the top just blew off. I'd attended to minor fires at the plant before—ones they didn't report—and not once did I see any animals, especially mutts. Strays know where to stay to be safe and fed.
Agent Griffith nods, jotting something down on his notepad. He taps his pen against the paper.
Agent Griffith: Did anyone from your squad approach? I know in the chaos of it all, it probably didn't cross your mind.
Pyanykh: You're right. We didn't approach. It approached us. Despite the fires, the radiation, and everything else, it ran up to us while we were preparing the hoses. We'd already been fighting the disaster for close to a day, and when this dog showed up, we thought we were collectively hallucinating. It barked, wagged its tail, and did everything a normal dog would do seeing new people. Just… right next to an open nuclear reactor. Our counters had been consistently clicking before that, of course, but the second the dog came over, the needle spiked higher than I'd seen that entire day. We thought something had happened inside again. Something that would send dust outside, or increase the fire's strength, or anything that would have explained why the radiation spiked. We almost retreated then, but we knew we had a duty to fulfill.
Agent Griffith: There was only one dog present, right? No other animals?
Pyanykh pauses, seeming to deliberate. He frowns.
Pyanykh: I could have sworn that off in the distance, I saw more dogs around the plant, far enough away that they might've not been mutts at all. There were at least three of them. It was in the direction your… anomaly came from. If I didn't know better, I'd say there were more of them, but if your people only found the one I saw, then maybe I was just hallucinating. I had more than enough radiation in my body for that to be a possibility.
Agent Griffith freezes, eyebrows drawing near. This is a new development.
Agent Griffith: Did anyone else see these other dogs?
Pyanykh: Yes, we all did, but we assumed there was any other explanation than us seeing radioactive dogs.
Agent Griffith: And what did the one that approached look like?
Pyanykh closes his eyes, drawing in a deep breath.
Pyanykh: Blue fur. That was the first thing we noticed. By all accounts, the dog looked pretty normal, but its fur was so blue that it was hard to pay attention to anything else for a moment.
Agent Griffith: How did you react to it?
Pyanykh: We hardly did. Our captain yelled at us to get a move on, so we left the dog behind. I didn't see it again after that. I heard when some of the liquidators tried to kill it before your facility took it in, it melted the bullets fired at it, but that's impossible.
Agent Griffith chuckles a bit. He crosses something off on his notepad.
Agent Griffith: I think the existence of the dog already proves many things impossible, my friend, but I see your point. I wouldn't believe anything in this building existed if I hadn't seen them with my own eyes. I can tell you that the dog can't melt bullets, though. There have been extensive tests to see if that's possible. And did anyone experience any… symptoms?
Pyanykh: It was all over in less than two minutes. The two men closest to the dog died with doses of over eleven hundred roentgen.
Agent Griffith: You don't think that was just from the plant itself?
Pyanykh's expression grows grim, his eyebrows tightening, almost as if the memory pains him.
Pyanykh: We never went on the roof. We were fighting fires from the ground while other men went onto the roof. The other men, farther away from us, got away with next to nothing. Us…
Pyanykh pauses, swallowing.
Pyanykh: Well, it was a long road to recovery, I'll say that.
<End Log>
Note: Agent Griffith was instructed to protect the secrets of the anomalies as best he could. While Valery knows of the subject's existence, the Foundation doesn't want him knowing the specifics of the subject's abilities in fear of it spreading. Deception may have been used if necessary.
Addendum 9427-03: Recovered Testing Logs
Addendum 9427-04: Recovered Testing Logs
Addendum 9427-05: Recovered Testing Logs
WARNING: THE FOLLOWING FILE IS LEVEL 4 CLASSIFIED
ANY ATTEMPT TO ACCESS THIS FILE WITHOUT LEVEL 4 AUTHORIZATION WILL BE LOGGED AND WILL LEAD TO IMMEDIATE DISCIPLINARY ACTION.
URGENT - 07/22/2025
Was patrolling the area around the plant today to search for anomalies after an anonymous report.
I stumbled upon another dog. They're present in the area, sure, and they're not an unfamiliar sight… but this one…
It had blue fur. I'm feeling a bit queasy now, so I'm going to send this letter along and rest. Couldn't get to a computer in time, but Sergeant ████████ is nearby and can deliver the message for me. Send personnel to the reactor as soon as possible.
- Sgt. ████████