Drogon, the Winged Shadow

Flying
As long as you control your commander, Drogon, the Winged Shadow gets +1/+1 and has menace.
When Drogon, the Winged Shadow attacks you may sacrifice another Dragon you control. If you do, put X +1/+1 counters on Drogon, the Winged Shadow where X is the sacrificed creature's power.