Arashin War Beast is a uncommon Creature — Beast card from Ugin's Fate (UGIN), collector number 123. Current market price: $0.25, TCGplayer market prices via Scryfall.
Whenever this creature deals combat damage to one or more blocking creatures, manifest the top card of your library. (Put it onto the battlefield face down as a 2/2 creature. Turn it face up any time for its mana cost if it's a creature card.)