Patrolling Peacemaker
{2}{W}Artifact Creature — Robot Soldier
This creature enters with two +1/+1 counters on it. Whenever an opponent commits a crime, proliferate. (They commit a crime if they target an opponent, anything an opponent controls, and/or cards in an opponent's graveyard. To proliferate, you choose any number of permanents and/or players, then give each another counter of each kind already there.)