Underworld Charger is a common Creature — Nightmare Horse card from Theros Beyond Death (THB), collector number 120. Current market price: $0.09 (foil $0.31), TCGplayer market prices via Scryfall.
This creature can't block. Escape—{4}{B}, Exile three other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.) This creature escapes with two +1/+1 counters on it.