Boneyard Avianist

Birds you control have Scavenge {x}, where
X is that creature's converted mana cost.
({x}, Exile that card from your graveyard: Put a number of +1/+1 counters equal to that card's power on target creature. Scavenge only as a sorcery.)
Mistmoore warriors never let a single bone or
scrap of flesh go to waste.