A Harpie Lady deck for the "Yu-Gi-Oh!" trading card game utilizes joint abilities to summon each other onto the field, destroy opponent's spell and traps cards, and each Harpie Lady card protects each other by increasing attack and defense points. The archetype was used primarily by Mai Valentine in the second season of the original "Yu-Gi-Oh!" series.
Harpie Lady cards are wind, winged beast and dragon-type monsters that rely on swarm tactics to overwhelm an opponent. Monster cards such as "Harpie's Pet Baby Dragon" and "Harpie's Pet Dragon" contain increasingly better effects when there are more Harpie Lady cards on the controller's field. "Harpie Lady Phoenix Formation" lets the controller destroy opponent's monster up to the number of Harpie Lady cards on the field. Each Harpie Lady monster is called "Harpie Lady" in the deck and on the field, which means the player is limited to a total of three Harpie Lady cards by rule.
One of the keys to a Harpie Lady deck is to summon the field spell card "Harpies' Hunting Ground" which allows users to destroy a spell and trap card each time a Harpie Lady card is summoned to the field by a normal or special summon. The card also increases the attack and defense of winged beast-type monsters. Other cards that amplify the effects of wind monsters and winged beast monsters are useful to Harpie Lady cards. As of August 2014, there are seven Harpie Lady cards in the "Yu-Gi-Oh!" trading card game.