Moonsong the Dream Drake

Flying, Hexproof.
During your End Phase, put a +1/+1 counter
on each tapped creature.
Each time a creature with a +1/+1 counter dies,
you gain 3 life and draw a card.
"It's said that some who hear its song dream
so sweetly they never wake."
-Han Ranferres, High Esaloth groundskeeper