SCP-3787-B describes an anomalous increase in horse aggression 
in free-roam horse populations. SCP-3787-B has been observed 
primarily in the mustang populations of Nevada, where the largest 
feral horse population in North America exists. Examples of 
aggression include unprovoked hostilities toward horses outside a 
constituent pack (leading to fatalities), the active killing of most or all 
members of a feral horse pack by that pack's dominant stallion, and 
in some cases, the cannibalization of foals as a show of 
dominance?. 


Increase in horse hostility has extended into normal horse feeding 
patterns as well. Feral horse packs affected by this anomaly will 


carry out apparently organized attacks on other wildlife as a means 
of feeding, escalating to the point of ignoring herbivorous feeding 
habits. This occurs despite horses being biologically unsuited for 
meat consumption in terms of their jaw structures and digestive 
systems. This manner of aggression has led to the progression of 
horses to the top of the food chain in many areas. 


SCP-3787-B appears to have initially begun in newborn foals 
affected by SCP-3787-A but has since transferred to an unknown 
number of horse populations of varying ages based on a geometric 
infection model. In addition, this anomaly has developed in the same 
time frame and area as a second equine anomaly. This anomaly, 
designated SCP-3787-, refers to the immediate consequences of a 
marked increase of total horse populations, which has led to the 
increase of the equine in the human consciousness. 


SCP-3787-e is the designation given to an anomalous memetic form 
of equinophobia. This is the emergence of an intense fear of horses 
among humans with no previous basis to fear horses. Individuals 
may not be aware that they have been affected by this anomaly until 
they have been re-exposed to the concept of horses through forms 
of media, or through personal conversations that reference horses. 


SCP-3787-€ occurs in suburban areas and urban centres, and 
among populations far from rural communities. More specifically, 
SCP-3787-€ occurs among populations with little access to that 
which is equine in nature’. Individuals within these populations with 
a fascination of horses on any level are not affected by this anomaly. 
An estimated 350,000 individuals within the continental United 
States (approximately 0.1% of the total population) are believed to 
have contracted this anomaly. 


Addendum 3787.1: On 2021/06/30, Foundation efforts to reduce 
the heightened equine birth rate were deemed successful, and the 
median horse gestation period levelled out to approximately 1.5 
times the baseline. In the two months since the anomaly was 
detected, approximately 450,000 new horses are believed to have 
been birthed in the United States alone. 


On 2021/07/12, domesticated horse populations began to contract 
what is hypothesized to be an anomalous illness. Horses affected by 


this illness experience a period of extreme stress, leaving them ina 

comatose state, and eventually killing them in approximately 18.5% 

of cases. Current trends predict that approximately 37% of horses in 
the Southern and Southwestern United States are afflicted with this 

illness. 


Research efforts into a cure for this illness have, as of 2021/07/29, 
proven ineffective. 


Addendum 3787.2: Since 2021/07/12, approximately 1.1 million 
horses in the US are believed to have been killed as a result of the 
accelerated spread of this illness. On 2021/08/10, Site-82, in 
conjunction with the Scientific Department, published a report 
regarding PROJECT: DIRE HORSE to SCiIPNET. A summary of the 
report is as follows. 


> Open report? 


Document 3787.0142: 
Summary of 
PROJECT: DIRE 
HORSE 


PROJECT: DIRE 
HORSE outlines the 
production of a 
significant synthetic 
horse population and 
the dissemination of 
this new population 
across the United 
States. This is to be 
done to substantially 
mitigate the ongoing 
loss of horse 
populations and to 
produce a phenotype 
resistant to the effects 
of the anomalous 
illness. To achieve this 


goal, DIRE HORSE has 
employed the use of 
Ashleigh's Fields, a 
cattle farm in Newton 
News, Montana, which 
has been operating 
under the Foundation 
front company Stratford 
Cattle Productions 
since 2010. Ashleigh's 
Fields uses an 
industrial farming 
facility responsible for 
the mass production of 
synthetic livestock in 
the place of modern 
farming techniques. 


DIRE HORSE makes 
use of the newly 
constructed Rimmer- 
Lister Hippological 
Simulacrum (RLHS) 
prototype. The RLHS is 
capable of producing 
500 artificially grown 
adult horses, or 
approximately 1,000 
foals, per hour, within 
99.91% genetic 
similarity of their natural 
counterparts. Horses 
produced by the RLHS 
are behaviorally 
engineered and 
memetically hardened 
to reduce the potential 
effects of an 
SCP-3787-B spread 
into its population. In 


the event of a runaway 
equine extinction due to 
SCP-3787, the RLHS 
and its sentinel facility 
at Aisleighfield Farms 
are capable of 
cryonically storing up to 
100,000 stable horses 
for a period of up to 10 
years. 


Further information on 
the technical and 
logistical specifications 
of the RLHS can be 
found in Document 
3787.0155. 


In an effort to reduce 
public awareness of the 
full extent of 
SCP-3787's spread, 
DIRE HORSE is to 
begin immediately to 
replace horse 
populations in 35 
different states. 
Information regarding 
this process is to be 
outlined in Document 
3787.0157. Any expired 
horses having come 
into contact with 
SCP-3787 are to be 
collected and sent to 
Site-41 for 
decommissioning 
purposes. 


> LEVEL 4 CLEARANCE REQUIRED 


Document 3787.0159: 
Decommissioning 
Report 


To prevent 
environmental 
contamination, any 
expired horses believed 
to have been affected 
by SCP-3787 at any 
point in their lifespan 
are to be tagged and 
collected for 
decommissioning 
purposes. The nature 
of this 
decommissioning is as 
follows: 


¢ Foundation 
personnel 
planted in various 
positions in the 
North American 
Horse Industry 
are to make note 
of all areas 
affected by mass 
die-offs due to 
SCP-3787. 

¢ The full extent of 
SCP-3787 effects 
in affected areas, 
including the 
number of 
expired horses, 
the source of the 
infection, and the 
speed of the 
infection's 


spread, is to be 
archived. 
Expired horses 
identified during 
this process are 
to be forcibly 
removed from the 
affected area on 
an immediate 
basis. 

Civilians aware of 
the full effect 
SCP-3787 has 
had on affected 
areas are to be 
amnesticized 
using Class-A 
Amnestics. 

Mass media 
blackouts 
regarding 
SCP-3787 are to 
be carried out, 
such that any 
uncontained 
reports on 
SCP-3787 are to 
be purged by a 
network of 
Foundation web 
crawlers. 

Expired horses 
are to be taken to 
Site-41 for 
neutralization. 
Neutralization is 
outlined below. A 
randomly 
selected pool of 
approximately 


1,100 expired 
horses (0.1% of 
all horses killed 
by SCP-3787) 
are to be stored 
for future testing. 


Neutralization efforts 
are to be carried out 
with the end goal of 
destroying all expired 
horses affected by 
SCP-3787. As per 
Procedure: IRISH 
WRISTWATCH, all 
destroyed subjects are 
to be summarily broken 
down into a component 
slurry to begin the 
transformation into 
Class-W, -X, and -Y 
mnestics material, as 
the primary component 
of modern mnestics is 
an admixture of various 
parts of horse 
anatomy‘. As of 
2021/08/20, this aspect 
of PROJECT: DIRE 
HORSE has been 
taken over by the 
Antimemetics Division. 


Addendum 3787.3: On 2021/09/03 at 01:04 AM, unknown 
anomalous entities attempted to force access into Site-41 before 
being repelled by automated lockdown procedures. A transcript of 
the encounter, as recorded by on-site surveillance, is as follows. 


> Open transcript? 


VIDEO LOG 


Note: Due to the high volume of 
antimemetic anomalies on-site, all 
cameras at Site-41 are outfitted 
with a Mariotte-Pashler 
antimemetic perception filter, as 
well as standard night vision. This 
allows for the surveillance of most 
documented forms of antimemetic 
or counterconceptual anomalies. 
For the sake of identification 
purposes, the cameras outline 
anomalies corresponding to this 
description in red. 


<Begin Log, 01:04 AM> 


A large wheel-shaped entity 
comes into view approximately 
350 meters from Site-41§. The 
entity is identified by a contrasting 
red against the green hue of the 
surveillance footage. The wheel- 
like anatomical structure bypasses 
a surveillance pylon by rolling 
through it at approximately 50 km/ 
h, taking out two of the pylon's 
legs. Security alarms begin to emit 
a high-pitched whine as the entity 
continues toward the site, at which 
point it begins to slow. 


MTF-Chai-10 ("Oxygenated 
Morons"), a three-man fast- 
insertion unit, comes into view, 
approaching the entity ona 
military ATV outfitted with an M2 
heavy machine gun. At this point, 


they respond to visual and audio communication 
attempts. Agent Davis was instructed to attempt to make 
physical contact with Agents Gold and Johnston and 
attempt to retrieve them. Agent Davis made physical 
contact with Agent Gold at 00:39, coinciding with an 
earthquake of 7.7 magnitude, which damaged the 
mirrors and redirected the light. All passengers 
immediately vanished, along with the three agents. 


Further rescue attempts are currently suspended, pending review. 


« SCP-490 | SCP-491 | SCP-492 » 


the entity forms a ball and begins 
to expand. 


MTF-Chai-10 is fully aware of the 
entity due to excess mnestic 

emissions from Procedure: IRISH 
WRISTWATCH present in the air. 


MTF-Chai-10-1: What the fuck? 


MTF-Chai-10-2: Just fire, they 
took down our guard tower. 


MTF-Chai-10-3: Firing. 


MTF-Chai-10-3 fires a 5-second 
long burst at the entity, expelling 
75 rounds. The entity's outer layer 
makes a popping sound before 
loud equine vocalizations are 
emitted from the deflated form. An 
individual entity separates from the 
larger entity and gallops towards 
MTF-Chai-10. 


MTF-Chai-10-2: A horse? What 
the fuck? 


MTF-Chai-10-2, who is operating 
the vehicle, begins to reverse, 
before circling the larger entity in a 
wide arc. The individual entity 
matches speed and chases the 
unit for approximately forty 
seconds, before latching itself to 
the back of the ATV. The larger 
entity then disappears from view. 


MTF-Chai-10-3 fires a 10-second 
burst directly at the individual 
entity, expelling 150 rounds. At 


this point, the entity is noted to 
break apart into multiple smaller 
portions. The scattered portions 
continue to move, implanting 
themselves onto various places of 
the ATV. 


MTF-Chai-10-2: Keep firing. 


MTF-Chai-10-3: The thing's Swiss 
cheese, | don't have anything to 
fire at! 


Smaller portions of the entity enter 
open sections of the ATV. 
Eventually, the ATV ceases 
operation. 


MTF-Chai-10-2: Alright, everyone 
out. Let's head behind the blast 
doors before the automated 
systems kick in. 


MTF-Chai-10-1: Right, let's move. 


MTF-Chai-10-3: That thing gave 
me the creeps. But where did the 
other bogey go? 


MTF-Chai-10-2: Not sure. Let's 
go. 


MTF-Chai-10 exits the ATV and 
makes their way to the side of 
Site-41. They enter through a 
large blast door, which 
automatically reinforces itself upon 
closing. Outside, the visible entity 
remains latched to the ATV, slowly 
squeezing the rest of its body into 
the vehicle. Equine vocalizations 


continue for the next 10 minutes. 


After 10 minutes, the larger entity 
appears approximately 100 meters 
from the facility. The entity takes 
the form of a large ball 
approximately 2 meters in 
diameter. 


The entity begins to roll towards 
the facility, gaining incredible 
speed. It moves towards the site at 
approximately 100 km/h, impacting 
the side of the facility and causing 
structural damage. The camera 
shakes from the impact, sending it 
offline. Audio surveillance 
continues. 


Site systems at this point log the 
activation of high-powered 2000W 
floodlights located around the 
facility. This is an automated 
feature to prevent intruders via 
disorientation before weaponized 
systems activate. 


Audio surveillance picks up a 
sharp equine vocalization, loud at 
first, but eventually becoming faint. 
It is thought at this point that the 
entity must have been damaged 
by the light, and retreated 
accordingly, before exiting the 
audio surveillance's effective 
range. 


<End Log, 01:26 AM> 


Closing Remarks: No further 


sightings of the larger entity have 
been reported after 01:26 AM. By 
morning, when lockdown lifted, an 
investigation into the entity within 
the ATV was completed. The 
entity within the ATV was found 
blackened and shrivelled, 
apparently terminated by 
prolonged exposure to the intense 
light. Extended research into the 
nature of these entities, which 
have been individually designated 
as SCP-3787-n, has begun. 


Addendum 3787.4: On 2021/09/05, individuals known to be 
affected by SCP-3787- experienced a spontaneous shift in 
anatomy, becoming more equine in nature. Not all affected 
individuals were able to make a full transformation’, with some 
expiring before the full transformation became possible. Individuals 
undergoing this transformation have been given the designation 
SCP-3787-e-1. 


In addition to this, Foundation personnel specializing in 
antimemetics training have begun to make note of large numbers of 
SCP-3787-n. These entities have begun to appear en masse as a 
direct result of extended Foundation efforts to control North 
American horse population numbers’. The appearance of these 
entities has prompted the reclassification of SCP-3787 to a Hiemal- 
class anomaly. 


A full description of SCP-3787-n is as follows. 
> Description of SCP-3787-n 


SCP-3787-n Description: Each 
instance of SCP-3787-n is part of 
a collective of highly predatory 
anomalous organisms. SCP-3787- 
n are vaguely humanoid equine 
entities, each composed of a 
highly malleable cartilage structure 


integrated with groupings of 
musculature typical of the common 
horse. Instances are covered in a 
thin epidermis with slight brown 
colouration. 


A defining feature of SCP-3787-n 
is the cranium, which is similar in 
shape to that of a horse, but on a 
smaller scale. At the bottom of the 
cranium is a muzzle of equine 
nature, from which equine 
vocalizations are possible. As well, 
naturally occurring braided hair 
similar in consistency to that of 
horsehair is visible in the form of a 
mane and a tail. Each individual 
strand of horsehair is apparently 
autonomous, despite SCP-3787- 
n's efforts to remain static in its 
positioning. 


While SCP-3787-n have dull 
rounded teeth, instances have 
been observed to take part in 
strictly carnivorous activities. 
Instances will mainly consume 
human beings, but have also been 
observed to consume instances of 
SCP-3787-e-1. Despite this, 
however, SCP-3787-n do not 
appear to feed for sustenance 
purposes, and instead, choose to 
hunt for recreational purposes. 


All appendages, including the 
arms, legs, and tail, are fully 
capable of being contorted, 
elongated, and wrapped around 
themselves. The extent of this 


manipulation is detailed below. 


Each instance of SCP-3787-n 
attacks in a manner solely 
involving their bodies, or in 
conjunction with other SCP-3787-n 
as a group. Despite their intelligent 
nature, the use of tools or 
equipment by SCP-3787-n has not 
been observed.