Mermaid Archer (SDRE-EN011) - Structure Deck: Realm of the Sea Emperor 1st Edition

Once per turn, you can equip 1 Level 3 or lower monster you control to this card. If you do, this card gains 800 ATK. If this card would be destroyed, you can destroy the equipped monster instead. (You can only equip 1 monster at a time to this card.)