If this card is Normal or Special Summoned: You can target 1 monster your opponent controls with lower DEF than this card’s ATK; change it to face-down Defense Position. If this card attacks a Defense Position monster, inflict piercing battle damage. If this card destroys a monster by battle: You can Special Summon 1 Level 4 or lower DARK Fiend monster from your GY in Defense Position. You can only use each effect of "Hook Horror" once per turn.