Dragonbroods' Relic is a uncommon Artifact card from Tarkir: Dragonstorm (TDM), collector number 140. Current market price: $0.23 (foil $0.19), TCGplayer market prices via Scryfall.
{T}, Tap an untapped creature you control: Add one mana of any color. {3}{W}{U}{B}{R}{G}, Sacrifice this artifact: Create a 4/4 Dragon creature token named Reliquary Dragon that's all colors. It has flying, lifelink, and "When this token enters, it deals 3 damage to any target." Activate only as a sorcery.