Flying
Whenever a Dragon you control dies while Boneyard Scourge is in your graveyard, you may pay {1}{B}. If you do, return Boneyard Scourge from your graveyard to the battlefield.
If Boneyard Scourge dies at the same time as another Dragon you control, its ability won’t trigger.
If Boneyard Scourge leaves your graveyard before its triggered ability resolves, it won’t be returned to the battlefield.