Most phi in Thai village folklore live in a specific place or wait for a specific circumstance, a haunted grove, a lonely stretch of road, a house where someone died badly. Phi pop is different, and that difference is exactly what has made it consequential: it is said to live inside a person, an ordinary neighbor, transmitted along a family bloodline or picked up by eating food a carrier prepared, so that suspicion falls on the living rather than on a place. A person thought possessed was traditionally described as craving raw meat and, in the belief's most extreme form, as attacking and devouring entrails, their own or an animal's, with agonizing stomach pain read as the visible symptom of the spirit working within them. A village mor phi, a ritual specialist, could be called to diagnose the possession and attempt an exorcism, but diagnosis itself carried weight beyond the ritual: once a family gained a reputation for harboring phi pop, that reputation could outlast any single healing attempt, affecting who would marry into the family, do business with them, or eat food they had touched. Phya Anuman Rajadhon, whose fieldwork founded modern academic study of Thai folklore, recorded phi pop belief as part of a wider pattern in which supernatural accusation and ordinary social friction, a land dispute, a personal grudge, an unexplained illness, became difficult to separate. This atlas describes phi pop as the folklore it is and as the real social pattern scholars have documented around it, without offering any ritual instruction for diagnosing, accusing or attempting to exorcise anyone, since the belief's documented history of harm to real people is part of what makes it worth understanding rather than something to reproduce.