Knightshade

Flying
When Knightshade enters the battlefield,
sacrifice a creature. Put a number of +1/+1
counters on Knightshade equal to the sacrificed
creature's power. When Knightshade takes
damage, remove that many +1/+1 counters
from it.
When Knightshade is put into a graveyard from
the battlefield, return one creature from your
graveyard to your hand.