Briar Shield 
Enchantment — Aura
Enchant creature Enchanted creature gets +1/+1. Sacrifice this Aura: Enchanted creature gets +3/+3 until end of turn.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL
Enchantment — Aura
Enchant creature Enchanted creature gets +1/+1. Sacrifice this Aura: Enchanted creature gets +3/+3 until end of turn.