Shanid, Sleepers' Scourge is a mythic Legendary Creature — Human Knight card from Dominaria United Commander (DMC), collector number 4. Current market price: $2.29 (foil $2.75), TCGplayer market prices via Scryfall.
Menace Other legendary creatures you control have menace. Whenever you play a legendary land or cast a legendary spell, you draw a card and you lose 1 life.