Ox of Agonas is a mythic Creature — Ox card from Theros Beyond Death Promos (PTHB), collector number 147p. Current market price: $0.98 (foil $1.67), TCGplayer market prices via Scryfall.
When this creature enters, discard your hand, then draw three cards. Escape—{R}{R}, Exile eight other cards from your graveyard. (You may cast this card from your graveyard for its escape cost.) This creature escapes with a +1/+1 counter on it.