When this card is destroyed by battle with an opponent's monster: You can take control of that opponent's monster, and if you do, it becomes a Zombie monster, also its ATK/DEF become 0. When your Zombie monster is destroyed by battle with an opponent's monster, while this card is in your GY: You can banish this card; take control of that opponent's monster, and if you do, it becomes a Zombie monster, also its ATK/DEF become 0. You can only use this effect of "Devouring Sarcoughagus" once per turn.