the ghost of Nang NakRefers to Nang Nak, a famous ghost from Thai folklore and the film Nang Nak. อี is a vulgar or derogatory female prefix, so this phrase is informal and potentially offensive.
TH: เขาเล่าเรื่องผีอีนากให้เด็ก ๆ ฟังก่อนนอน
EN: He told the children the story of Nang Nak's ghost before bed.