Giant Oyster [Time Spiral Timeshifted]

Set: Time Spiral Timeshifted Type: Creature — Oyster Rare Cost: {2}{U}{U} You may choose not to untap Giant Oyster during your untap step. {T}: For as long as Giant Oyster remains tapped, target tapped creature doesn't untap during its controller's untap step, and at the beginning of each of your draw steps, put a -1/-1 counter on that creature. When Giant Oyster leaves the battlefield or becomes untapped, remove all -1/-1 counters from the creature.