Cárnan, Goddes of Instinct

Flying, Protection from Green.
At the beginning of each end step, put two -1/-1 counters on the creature with the highest
power on the battlefield. If a creature you control
dies this way, you may return a card with
converted mana cost equal or less than the
amount of -1/-1 counters on it to your hand.
{2}: Target creature an opponent controls gets
+3/+0 until the end of turn. Any player
may activate this ability.