The Plat-eye is a malicious, ghostly Black Dog from the folklore of the West Indies, Georgia and South Carolina.
In its true form, a Plat-eye only has a single flat eye in the middle of its forehead, like a plate.
Plat-eyes wander lonely roads, sometimes restricted to their own gravesites, in the shape of an animal. Most often this animal is a dog with blazing eyes. It could also manifest as the ghost of the human it once was, a cat, a cow, or a person with no head. At other times the spirit was invisible except for its fiery eyes, which were considered the best way to identify an animal as being a disguised Plat-eye. Sometimes the spirit takes no shape at all, only a freezing, suffocating mist.
A Plat-eye is created whenever a person dies without a proper burial or is buried carelessly, unsettling their spirit. The angry ghost of the person manifests as a malicious, shapeshifting being that harasses the people who failed to bury it decently. At other times, it is the remnants of a person who has unfinished business on earth, wants to cause trouble, or died unjustly and wishes to avenge its own death. It wanders the place of its burial, unable to find rest, terrorizing passersby.
Unlike many black dog spirits, the Plat-eye is purely malevolent or at least vengeful; sometimes it only seeks justice and the punishment of those who wronged it in life, but at other times it is a simple killer. Its appearances are linked to the new moon. In some sources, only people born with a caul over their heads could see the Plat-eye in its true form.
Plat-eyes bent on vengeance would exclusively hunt the people that they blamed for their deaths, but others were more indiscriminate in their choice of prey.
If a person encounters a Plat-eye, the spirit will begin to grow to an immense size, eventually enveloping and consuming the victim. At other times the Plat-eye follows the person without doing any harm. Sometimes it would harass and torment them, driving them insane. Especially powerful Plat-eyes could suck out the souls of humans.
The Plat-eye could shapeshift and grow to an impossible size, which is how it caught victims. The only way to stop a Plat-eye was to find the corpse of the person it once was and give it a proper burial. This would cause the spirit to end its quest for vengeance and move on. At other times, the punishment of the person who killed or otherwise offended the Plat-eye's living form would calm the creature.