Bloodgem Wyvern

Flying, Protection from white
Each time Bloodgem Wyvern deals damage to a player, create a Bloodgem artifact token. At the begining of your turn, sacrifice a Bloodgem
token. Then, put a creature card from your
graveyard onto the battlefield under your
command. If a Bloodgem token can't be
sacrificed, or, there are no creature cards in
your graveyard, you lose 2 life instead.