Living Artifact is a rare Enchantment — Aura card from 30th Anniversary Edition (30A), collector number 501. Current market price: $19.95, TCGplayer market prices via Scryfall.
Enchant artifact Whenever you're dealt damage, put that many vitality counters on this Aura. At the beginning of your upkeep, you may remove a vitality counter from this Aura. If you do, you gain 1 life.