A supernatural creature that brings harm or misfortune; used in folklore, fantasy, and metaphorically for dangerous things.
A demon appeared from deep within the forest.
It is said that a demon lives in that forest.
He kept drinking as if possessed by the demon of alcohol.
The hero defeated the demon that was attacking the village.
He suddenly went berserk as if possessed by a demon.
This eerie incident is surely the work of a demon.
妖怪 refers to traditional Japanese folklore spirits and apparitions that are often mischievous rather than evil, while 魔物 stresses a harmful or malevolent supernatural nature.
魔物 is a broader native term for any monstrous or evil supernatural creature, whereas デーモン specifically evokes a demon figure from Western mythology or fantasy fiction.
魔物 covers any monstrous or supernatural creature with evil power, while 悪霊 is narrower, referring only to a malevolent disembodied spirit.
化け物 often refers to a shape-shifting apparition or freakish creature, sometimes used loosely for anything monstrous, while 魔物 more specifically denotes an evil, supernatural being that causes harm.
Laplace's demon
Compound of 魔 (ma, 'demon, evil spirit') and 物 (mono, 'thing, creature'). The exact historical derivation is uncertain, but the kanji combination has been used since at least the Heian period to refer to supernatural beings that cause harm.