Prosperous Innkeeper is a uncommon Creature — Halfling Citizen card from The List (PLST), collector number BLC-121. Current market price: $0.26, TCGplayer market prices via Scryfall.
When this creature enters, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.") Whenever another creature you control enters, you gain 1 life.