MacCready, Lamplight Mayor is a rare Legendary Creature — Human Advisor card from Fallout (PIP), collector number 108. Current market price: $4.02 (foil $6.46), TCGplayer market prices via Scryfall.
Whenever a creature you control with power 2 or less attacks, it gains skulk until end of turn. (It can't be blocked by creatures with greater power.) Whenever a creature with power 4 or greater attacks you, its controller loses 2 life and you gain 2 life.