SCP-1156 is a male domesticated horse (Equus ferus caballus) of indeterminate breed and age, approximately 1.7 meters tall. It describes itself as a professional coach horse and is convinced that the Foundation employs it for this purpose. Its tongue, palate, lips, and vocal cords are shaped in a manner not seen in non-anomalous horses, enabling it to produce phonemes used in human speech. Its brain is approximately ##% larger than that of a normal horse and possesses several anatomical regions of unknown function or purpose.

SCP-1156 appears to speak with a thick accent resembling that of the natives of the East End of London, UK (“Cockneys” in common use) prior to its acquisition by the Foundation. It claims to have been born and bred in the London borough of Whitechapel, and that it was a member of a community of sapient horses that lived openly throughout the area before its capture by the Foundation. It has demonstrated the ability to manipulate tools and simple machines with its mouth, lips, and tongue, and can write by holding a pen in its mouth.

It is believed that Long Horse is a messenger sent to warn humans of impending dangers. When a human sees or hears its neck cracking, it is a sign that disaster will soon befall them. If a person sees or hears Long Horse moving, it is a sign that it is heading somewhere to deliver its message.

Trevor Henderson, the artist who created Long Horse, is known for creating various bizarre creatures over the internet. He has also created Siren Head, Cartoon Cat, and the Country Road Creature. Trevor has confirmed that Long Horse and Siren Head are aware of one another, and have been known to interact with each other on occasion.

Long Horse is currently housed in a stable adjacent to the Secure Outdoor Testing Facility at Site 73. It is provided with food, water, bedding, grooming, and veterinary care appropriate for a non-anomalous animal of its species. It is granted supervised access to the facility for exercise and grazing purposes during daylight hours when no testing is scheduled. Any clothing changes exhibited by SCP-1156 are to be documented and monitored.

SCP-1156 is to be paid twice a week in currency equaling the minimum wage in the United Kingdom, less the amount of legally required deductions for housing and pension. Failure to cooperate with the staff of the Foundation will result in the loss of its privileges as listed above.