Sakiko, Mother of Summer is a rare Legendary Creature — Snake Shaman card from Commander Masters (CMM), collector number 319. Current market price: $0.42 (foil $0.78), TCGplayer market prices via Scryfall.
Whenever a creature you control deals combat damage to a player, add that much {G}. Until end of turn, you don't lose this mana as steps and phases end.