Discord, Lord of Disharmony is a mythic Legendary Creature — Chimera card from Secret Lair Drop (SLD), collector number 798. Current market price: $32.57 (foil $36.35), TCGplayer market prices via Scryfall.
Flying At the beginning of your end step, choose a random nonland Magic card name. Until your next end step, you may cast a copy of a spell with that name, and mana of any type can be spent to cast it. If you cast a spell this way, copy this ability if Discord is on the battlefield.