Spawning Brood

Enchant target creature an opponent controls.
Tap creature. It doesn't untap during your
opponent's untap step.
At the start of each of your turns, you may pay {g}. If you do, the tapped creature gets a -1/-1
counter and you may create a 1/1 Green
Spiderling token with Reach and place it onto
the battlefield under your control.