Elite Scaleguard is a uncommon Creature — Human Soldier card from March of the Machine Commander (MOC), collector number 181. Current market price: $0.27, TCGplayer market prices via Scryfall.
When this creature enters, bolster 2. (Choose a creature with the least toughness among creatures you control and put two +1/+1 counters on it.) Whenever a creature you control with a +1/+1 counter on it attacks, tap target creature defending player controls.