Mightstone's Animation is a common Enchantment — Aura card from The Brothers' War (BRO), collector number 58. Current market price: $0.13 (foil $0.21), TCGplayer market prices via Scryfall.
Enchant artifact When this Aura enters, draw a card. Enchanted artifact is a creature with base power and toughness 4/4 in addition to its other types.