Graydle Alligator (DOCS-EN033) [Dimension of Chaos]

If this card in your Monster Zone is destroyed by battle or a Spell 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 a monster by this effect, destroy the equipped monster.