Graydle Cobra (DOCS-EN034)

If this card in your Monster Zone is destroyed by battle or a Trap Card's effect and sent to the Graveyard: You can target 1 face-up monster your opponent controls; equip this card from your Graveyard to that monster. While this card is equipped to a monster by this effect, take control of that monster. When this card leaves the field while equipped to an opponent's monster by this effect, destroy the equipped monster.