Herd Heirloom is a rare Artifact card from Tarkir: Dragonstorm Promos (PTDM), collector number 144p. Current market price: $4.38 (foil $4.15), TCGplayer market prices via Scryfall.
{T}: Add one mana of any color. Spend this mana only to cast a creature spell. {T}: Until end of turn, target creature you control with power 4 or greater gains trample and "Whenever this creature deals combat damage to a player, draw a card."