Brokkos, Apex of Forever is a mythic Legendary Creature — Nightmare Beast Elemental card from Ikoria: Lair of Behemoths Promos (PIKO), collector number 179p. Current market price: $2.32 (foil $2.12), TCGplayer market prices via Scryfall.
Mutate {2}{U/B}{G}{G} (If you cast this spell for its mutate cost, put it over or under target non-Human creature you own. They mutate into the creature on top plus all abilities from under it.) Trample You may cast this card from your graveyard using its mutate ability.