Sygg, River Cutthroat is a rare Legendary Creature — Merfolk Rogue card from Shadowmoor (SHM), collector number 176. Current market price: $12.12 (foil $290.19), TCGplayer market prices via Scryfall.
At the beginning of each end step, if an opponent lost 3 or more life this turn, you may draw a card. (Damage causes loss of life.)