Stalwart Successor is a uncommon Creature — Human Warrior card from Tarkir: Dragonstorm (TDM), collector number 227. Current market price: $0.19 (foil $0.32), TCGplayer market prices via Scryfall.
Menace (This creature can't be blocked except by two or more creatures.) Whenever one or more counters are put on a creature you control, if it's the first time counters have been put on that creature this turn, put a +1/+1 counter on that creature.