The Elder Scrolls: Tamriel real

This cursed ring binds its wearer to a nightmarish fate, causing them to be relentlessly pursued by a horrific monster from the dark corners of their own imagination. Only the wearer can see this monster, which can vary in size and is considered CR 30. Instilling the cursed hunted person with absolute fear and dread for every moment they wear the ring. It is possible to elude the monster for a brief respite, but it will always find the one bound to this ring where ever they hide.