Evil spirits (6)
(Other definitions for fiends that I've seen before include "fanatics" , "Addicts; devotees" , "Devils, monsters" , "Cruel people or evil spirits" , "Very wicked or cruel people" .)
'evil spirits' is the definition.
(ghoul is a kind of evil spirit)
This is the entire clue.
(Other definitions for ghouls that I've seen before include "Evil spirits that rob graves and eat corpses" , "Evil spirits or people interested in morbid things" , "Mythical creatures that devour corpses" , "They're interested in horrible things" , "Malevolent spirits" .)
'evil spirits' is the definition.
(incubus is a kind of evil spirit)
This is all the clue.
(Other definitions for incubi that I've seen before include "nightmares" , "Demons of the night" .)
'evil spirits' is the definition.
(demon is a kind of evil spirit)
This is all the clue.
(Other definitions for demons that I've seen before include "Evil spirits, devils" , "Evil supernatural beings" , "Fiends or devils" , "Wicked people" .)
'evil spirits' is the definition.
(devil is a kind of evil spirit)
This is all the clue.
(Other definitions for devils that I've seen before include "wicked people" , "Former French penal colony" , "'Demons, fiends (6)'" , "Evil supernatural beings" , "Evil spirits" .)