Barbed Foliage 
Enchantment
Whenever a creature attacks you, it loses flanking until end of turn. Whenever a creature without flying attacks you, this enchantment deals 1 damage to it.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL