Boneshard Slasher 
Creature — Horror
Flying Threshold — As long as seven or more cards are in your graveyard, this creature gets +2/+2 and has "When this creature becomes the target of a spell or ability, sacrifice it."
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL