Horace Slughorn

Professor (Whenever a nontoken creature enters
the battlefield with a lower power or toughness
than this creature, put a +1/+1 counter on it)
At the beginning of your first main phase put 2
+1/+1 counters on target creature, return an
instant or sorcery from your graveyard to your
hand and put 2 -1/-1 counters on target creature.