Ivy's Bat Trap

Wither
Whenever a creature with -1/-1 counters on it
dies, put a number of +1/+1 counters on
Ivy's Bat Trap equal to the number of counters
on that creature.
When Ivy's Bat Trap Dies, create X 0/1 Plants
where X is equal to the number of
counters on Ivy's Bat Trap