Grim Poppet (Voodo Doll)

Whenever a creature dies, if it had a -1/-1 counter on it, put a -1/-1 counter on target creature.

This creature enters with three -1/-1 counters on it. Remove a -1/-1 counter from this creature: Put a -1/-1 counter on another target creature.

Flying Wither (This deals damage to creatures in the form of -1/-1 counters.) Creatures your opponents control with counters on them can't attack or block.

Enchant creature : Put a -1/-1 counter on enchanted creature.

At the beginning of your upkeep, destroy target creature with a -1/-1 counter on it.

Wither (This deals damage to creatures in the form of -1/-1 counters.) Whenever a creature an opponent controls with a -1/-1 counter on it dies, you may return that card to the battlefield under your control.