Traditional Chinese society constructed a "spiritual" or "supernatural" world made up of "Heavenly Gods," "Spirits of the Earth," and "Human Ghosts." In addition to these beings were also the so-called mei魅, which are somewhat similar to the fairies or monsters in Western civilization. This philological study of terms associated with mei reveals that the notion of mei can be traced to pre-Qin 秦 China (pre-221 BC). Three basic terms referring to these beings emerged during the Han Dynasty (202 BC-AD 220), namely chimei魑魅 (monster), guimei鬼魅 (ghostly monster) and jingmei精魅 (fairy), and it was during the Han Dynasty that the meanings of these terms reached maturity and became more firmly established.
Basically, mei refers to a type of non-human monstrous creature; Regarded as "goblins" or "demons" that brought about accidents, confusion, illness, disasters, and disruption, these "beings" were seen as rare, mysterious, and strange. Yet the three concepts of chimei, guimei, and jingmei clearly differ.
Chimei were originally thought to have existed in "foreign lands" or "remote places," and it was only later that they entered the mountains and rivers of "China" proper.
Chimei were "creatures" with particular forms, mostly those of animals or creatures that were half-human and half-beast.