Mandy the Duskwing Marauder

Flying
Whenever a creature an opponent controls enters
the battlefield under their control, if that
creature's power is less than Mandy's power, you
may have Mandy deal 2 damage to that creature.
Whenever Mandy deals combat damage to a
player, put a +1/+1 counter on it.
"From twilight to dawn, its domain is marked in
blood and shadows."