Argivian Cavalier is a common Creature — Orc Knight card from Dominaria United (DMU), collector number 4. Current market price: $0.17 (foil $0.08), TCGplayer market prices via Scryfall.
Enlist (As this creature attacks, you may tap a nonattacking creature you control without summoning sickness. When you do, add its power to this creature's until end of turn.) When this creature enters, create a 1/1 white Soldier creature token.