Splendor Mare is a uncommon Creature — Elk Unicorn card from Ikoria: Lair of Behemoths (IKO), collector number 32. Current market price: $0.30 (foil $0.38), TCGplayer market prices via Scryfall.
Lifelink Cycling {1}{W} ({1}{W}, Discard this card: Draw a card.) When you cycle this card, put a lifelink counter on target creature you control.