Mindless Conscription is a uncommon Enchantment card from Modern Horizons 3 (MH3), collector number 101. Current market price: $0.22 (foil $0.33), TCGplayer market prices via Scryfall.
When this enchantment enters and whenever you draw your third card each turn, amass Zombies 3. (Put three +1/+1 counters on an Army you control. It's also a Zombie. If you don't control an Army, create a 0/0 black Zombie Army creature token first.)