Grolnex, Grand Scourge

When Grolnex enters the battlefield, note the
amount of -1/-1 counters on creatures target
opponent controls. Then, target opponent gets
poison counters equal to the amount of -1/-1
counters that are on creatures that opponent
controls. (A player with ten or more poison counters
loses the game.)
"At last mighty Grolnex has been summoned!
Revel in the cycle that is life and death!"