Momentum 
Enchantment — Aura
Enchant creature At the beginning of your upkeep, you may put a growth counter on this Aura. Enchanted creature gets +1/+1 for each growth counter on this Aura.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL