Legion Vanguard is a common Creature — Vampire Soldier card from Commander Masters (CMM), collector number 170. Current market price: $0.18 (foil $0.16), TCGplayer market prices via Scryfall.
{1}, Sacrifice another creature: This creature explores. (Reveal the top card of your library. Put that card into your hand if it's a land. Otherwise, put a +1/+1 counter on this creature, then put the card back or put it into your graveyard.)