Mermaid Archer

WATER
Once per turn: You can target 1 face-up Level 3 or lower monster you control; equip that target to this card. (You can only equip 1 monster at a time to this card with this effect.) While equipped with a monster by this effect, this card gains 800 ATK. If this card would be destroyed, you can destroy the monster equipped to it with this effect, instead.
1200
200

Sea Serpent WATER Effect Monster 3 effect