Savra, Queen of the Golgari is a rare Legendary Creature — Elf Shaman card from GRN Guild Kit (GK1), collector number 69. Current market price: $5.28, TCGplayer market prices via Scryfall.
Whenever you sacrifice a black creature, you may pay 2 life. If you do, each other player sacrifices a creature of their choice. Whenever you sacrifice a green creature, you may gain 2 life.