SkullWalker Golem

Other creatures you control gain +2/+1

Whenever a creature you control dies deal 2 damage to all creatures Opponents control.

Whenever a creature an Opponent control dies, all other creatures you control gain +1/+0.

When a creature dies add a Counter to SkullWalker Golem.
When Skull walker Golem has 15 Counters on it Double its Power and Triple its toughness.