Lotus Ring is a mythic Artifact — Equipment card from The Big Score Promos (PBIG), collector number 24p. Current market price: $1.10 (foil $1.46), TCGplayer market prices via Scryfall.
Indestructible Equipped creature gets +3/+3 and has vigilance and "{T}, Sacrifice this creature: Add three mana of any one color." Equip {3}