Attuma, Atlantean Warlord is a uncommon Legendary Creature — Merfolk Warrior Villain card from Marvel Super Heroes (MSH), collector number 47. Current market price: $0.34 (foil $0.32), TCGplayer market prices via Scryfall.
Other Merfolk you control get +1/+1. Whenever one or more Merfolk you control attack a player, draw a card.