Merfolk Windrobber is a uncommon Creature — Merfolk Rogue card from Zendikar Rising (ZNR), collector number 70. Current market price: $0.17 (foil $0.30), TCGplayer market prices via Scryfall.
Flying Whenever this creature deals combat damage to a player, that player mills a card. (They put the top card of their library into their graveyard.) Sacrifice this creature: Draw a card. Activate only if an opponent has eight or more cards in their graveyard.