Namor, Scourge of the Seas is a rare Legendary Creature — Mutant Merfolk Villain card from Marvel Super Heroes Commander (MSC), collector number 631. Current market price: $0.89 (foil $4.12), TCGplayer market prices via Scryfall.
Flying Each other Merfolk you control with a +1/+1 counter on it has flying. At the beginning of combat on your turn, target creature you control connives. (Draw a card, then discard a card. If you discarded a nonland card, put a +1/+1 counter on that creature.)