Cold-Eyed Selkie is a rare Creature — Merfolk Rogue card from Modern Masters (MMA), collector number 186. Current market price: $0.47 (foil $14.55), TCGplayer market prices via Scryfall.
Islandwalk (This creature can't be blocked as long as defending player controls an Island.) Whenever this creature deals combat damage to a player, you may draw that many cards.