specter (n.)
- apparition
- appearance
- atua
- bogey
- bogeyman
- bugaboo
- bugbear
- daemon
- demon
- fantasy
- figure
- form
- genius
- ghost
- ghoul
- hobgoblin
- horror
- image
- incubus
- intelligence
- monster
- nightmare
- ogre
- ogress
- phantasm
- phantasma
- phantasmagoria
- phantom
- presence
- revenant
- scarecrow
- scarer
- shade
- shadow
- shape
- spirit
- succubus
- terror
- umbra
- vampire
- vision
- werewolf
- wraith