Namor, Atlantean King is a rare Legendary Creature — Mutant Merfolk Noble card from Marvel Super Heroes Commander (MSC), collector number 409. Current market price: $1.82, TCGplayer market prices via Scryfall.
Flying Whenever you cast a noncreature spell, create a 1/1 blue Merfolk creature token. Whenever Namor attacks a player who has more life than you, other creatures you control attacking that player get +2/+0 until end of turn.