Teething Wurmlet is a rare Creature — Wurm card from The Brothers' War Promos (PBRO), collector number 192p. Current market price: $0.39 (foil $0.27), TCGplayer market prices via Scryfall.
This creature has deathtouch as long as you control three or more artifacts. Whenever an artifact you control enters, you gain 1 life. If this is the first time this ability has resolved this turn, put a +1/+1 counter on this creature.