Preyseizer Dragon 
Creature — Dragon
Flying Devour 2 (As this creature enters, you may sacrifice any number of creatures. It enters with twice that many +1/+1 counters on it.) Whenever this creature attacks, it deals damage to any target equal to the number of +1/+1 counters on this creature.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL