ghost, monster

(ゆうれい) A ghost bent on revenge. The Ring.
(ようかい) Folk monster – scary but not usually dangerous. more like the European fairy.
おばけ A child’s word for ghost.
(あくりょう) A spirit who puts curses on people, or brings misfortune to entire towns, or possesses innocent fools. Unlike 幽霊, they don’t attack you directly, and unlike 妖怪 don’t have a physical form