Boneshard Slasher

Flying Threshold — As long as there are seven or more cards in your graveyard, this creature gets +2/+2 and has "When this creature becomes the target of a spell or ability, sacrifice it."

From Magic: The Gathering.

Open the interactive version on https://mythscribe.cloud/app/tcg/cards/cms6o6jai3rv1pb1h90n0p9us.